[JFFS2] Fix memory leak in scan code; improve comments.
[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
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                 DIRTY_SPACE(ofs);
573         }
574
575         /* Now ofs is a complete physical flash offset as it always was... */
576         ofs += jeb->offset;
577
578         noise = 10;
579
580         dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
581
582 scan_more:
583         while(ofs < jeb->offset + c->sector_size) {
584
585                 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
586
587                 cond_resched();
588
589                 if (ofs & 3) {
590                         printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs);
591                         ofs = PAD(ofs);
592                         continue;
593                 }
594                 if (ofs == prevofs) {
595                         printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs);
596                         DIRTY_SPACE(4);
597                         ofs += 4;
598                         continue;
599                 }
600                 prevofs = ofs;
601
602                 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
603                         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),
604                                   jeb->offset, c->sector_size, ofs, sizeof(*node)));
605                         DIRTY_SPACE((jeb->offset + c->sector_size)-ofs);
606                         break;
607                 }
608
609                 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
610                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
611                         D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
612                                   sizeof(struct jffs2_unknown_node), buf_len, ofs));
613                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
614                         if (err)
615                                 return err;
616                         buf_ofs = ofs;
617                 }
618
619                 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
620
621                 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
622                         uint32_t inbuf_ofs;
623                         uint32_t empty_start;
624
625                         empty_start = ofs;
626                         ofs += 4;
627
628                         D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs));
629                 more_empty:
630                         inbuf_ofs = ofs - buf_ofs;
631                         while (inbuf_ofs < buf_len) {
632                                 if (*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff) {
633                                         printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n",
634                                                empty_start, ofs);
635                                         DIRTY_SPACE(ofs-empty_start);
636                                         goto scan_more;
637                                 }
638
639                                 inbuf_ofs+=4;
640                                 ofs += 4;
641                         }
642                         /* Ran off end. */
643                         D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs));
644
645                         /* If we're only checking the beginning of a block with a cleanmarker,
646                            bail now */
647                         if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
648                             c->cleanmarker_size && !jeb->dirty_size && !jeb->first_node->next_phys) {
649                                 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size)));
650                                 return BLK_STATE_CLEANMARKER;
651                         }
652
653                         /* See how much more there is to read in this eraseblock... */
654                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
655                         if (!buf_len) {
656                                 /* No more to read. Break out of main loop without marking
657                                    this range of empty space as dirty (because it's not) */
658                                 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n",
659                                           empty_start));
660                                 break;
661                         }
662                         D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs));
663                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
664                         if (err)
665                                 return err;
666                         buf_ofs = ofs;
667                         goto more_empty;
668                 }
669
670                 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
671                         printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs);
672                         DIRTY_SPACE(4);
673                         ofs += 4;
674                         continue;
675                 }
676                 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
677                         D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs));
678                         DIRTY_SPACE(4);
679                         ofs += 4;
680                         continue;
681                 }
682                 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
683                         printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs);
684                         printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n");
685                         DIRTY_SPACE(4);
686                         ofs += 4;
687                         continue;
688                 }
689                 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
690                         /* OK. We're out of possibilities. Whinge and move on */
691                         noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
692                                      JFFS2_MAGIC_BITMASK, ofs,
693                                      je16_to_cpu(node->magic));
694                         DIRTY_SPACE(4);
695                         ofs += 4;
696                         continue;
697                 }
698                 /* We seem to have a node of sorts. Check the CRC */
699                 crcnode.magic = node->magic;
700                 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
701                 crcnode.totlen = node->totlen;
702                 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
703
704                 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
705                         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",
706                                      ofs, je16_to_cpu(node->magic),
707                                      je16_to_cpu(node->nodetype),
708                                      je32_to_cpu(node->totlen),
709                                      je32_to_cpu(node->hdr_crc),
710                                      hdr_crc);
711                         DIRTY_SPACE(4);
712                         ofs += 4;
713                         continue;
714                 }
715
716                 if (ofs + je32_to_cpu(node->totlen) >
717                     jeb->offset + c->sector_size) {
718                         /* Eep. Node goes over the end of the erase block. */
719                         printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
720                                ofs, je32_to_cpu(node->totlen));
721                         printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
722                         DIRTY_SPACE(4);
723                         ofs += 4;
724                         continue;
725                 }
726
727                 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
728                         /* Wheee. This is an obsoleted node */
729                         D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));
730                         DIRTY_SPACE(PAD(je32_to_cpu(node->totlen)));
731                         ofs += PAD(je32_to_cpu(node->totlen));
732                         continue;
733                 }
734
735                 switch(je16_to_cpu(node->nodetype)) {
736                 case JFFS2_NODETYPE_INODE:
737                         if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
738                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
739                                 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
740                                           sizeof(struct jffs2_raw_inode), buf_len, ofs));
741                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
742                                 if (err)
743                                         return err;
744                                 buf_ofs = ofs;
745                                 node = (void *)buf;
746                         }
747                         err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
748                         if (err) return err;
749                         ofs += PAD(je32_to_cpu(node->totlen));
750                         break;
751
752                 case JFFS2_NODETYPE_DIRENT:
753                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
754                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
755                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
756                                           je32_to_cpu(node->totlen), buf_len, ofs));
757                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
758                                 if (err)
759                                         return err;
760                                 buf_ofs = ofs;
761                                 node = (void *)buf;
762                         }
763                         err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
764                         if (err) return err;
765                         ofs += PAD(je32_to_cpu(node->totlen));
766                         break;
767
768 #ifdef CONFIG_JFFS2_FS_XATTR
769                 case JFFS2_NODETYPE_XATTR:
770                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
771                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
772                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)"
773                                           " 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_xattr_node(c, jeb, (void *)node, ofs, s);
782                         if (err)
783                                 return err;
784                         ofs += PAD(je32_to_cpu(node->totlen));
785                         break;
786                 case JFFS2_NODETYPE_XREF:
787                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
788                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
789                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)"
790                                           " left to end of buf. Reading 0x%x at 0x%08x\n",
791                                           je32_to_cpu(node->totlen), buf_len, ofs));
792                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
793                                 if (err)
794                                         return err;
795                                 buf_ofs = ofs;
796                                 node = (void *)buf;
797                         }
798                         err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
799                         if (err)
800                                 return err;
801                         ofs += PAD(je32_to_cpu(node->totlen));
802                         break;
803 #endif  /* CONFIG_JFFS2_FS_XATTR */
804
805                 case JFFS2_NODETYPE_CLEANMARKER:
806                         D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs));
807                         if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
808                                 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
809                                        ofs, je32_to_cpu(node->totlen), c->cleanmarker_size);
810                                 DIRTY_SPACE(PAD(sizeof(struct jffs2_unknown_node)));
811                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
812                         } else if (jeb->first_node) {
813                                 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset);
814                                 DIRTY_SPACE(PAD(sizeof(struct jffs2_unknown_node)));
815                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
816                         } else {
817                                 struct jffs2_raw_node_ref *marker_ref = jffs2_alloc_raw_node_ref();
818                                 if (!marker_ref) {
819                                         printk(KERN_NOTICE "Failed to allocate node ref for clean marker\n");
820                                         return -ENOMEM;
821                                 }
822                                 marker_ref->next_in_ino = NULL;
823                                 marker_ref->flash_offset = ofs | REF_NORMAL;
824
825                                 jffs2_link_node_ref(c, jeb, marker_ref, c->cleanmarker_size);
826
827                                 ofs += PAD(c->cleanmarker_size);
828                         }
829                         break;
830
831                 case JFFS2_NODETYPE_PADDING:
832                         if (jffs2_sum_active())
833                                 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
834                         DIRTY_SPACE(PAD(je32_to_cpu(node->totlen)));
835                         ofs += PAD(je32_to_cpu(node->totlen));
836                         break;
837
838                 default:
839                         switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
840                         case JFFS2_FEATURE_ROCOMPAT:
841                                 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
842                                 c->flags |= JFFS2_SB_FLAG_RO;
843                                 if (!(jffs2_is_readonly(c)))
844                                         return -EROFS;
845                                 DIRTY_SPACE(PAD(je32_to_cpu(node->totlen)));
846                                 ofs += PAD(je32_to_cpu(node->totlen));
847                                 break;
848
849                         case JFFS2_FEATURE_INCOMPAT:
850                                 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
851                                 return -EINVAL;
852
853                         case JFFS2_FEATURE_RWCOMPAT_DELETE:
854                                 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
855                                 DIRTY_SPACE(PAD(je32_to_cpu(node->totlen)));
856                                 ofs += PAD(je32_to_cpu(node->totlen));
857                                 break;
858
859                         case JFFS2_FEATURE_RWCOMPAT_COPY: {
860                                 struct jffs2_raw_node_ref *ref;
861                                 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
862
863                                 ref = jffs2_alloc_raw_node_ref();
864                                 if (!ref)
865                                         return -ENOMEM;
866                                 ref->flash_offset = ofs | REF_PRISTINE;
867                                 ref->next_in_ino = 0;
868                                 jffs2_link_node_ref(c, jeb, ref, PAD(je32_to_cpu(node->totlen)));
869
870                                 /* We can't summarise nodes we don't grok */
871                                 jffs2_sum_disable_collecting(s);
872                                 ofs += PAD(je32_to_cpu(node->totlen));
873                                 break;
874                                 }
875                         }
876                 }
877         }
878
879         if (jffs2_sum_active()) {
880                 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
881                         dbg_summary("There is not enough space for "
882                                 "summary information, disabling for this jeb!\n");
883                         jffs2_sum_disable_collecting(s);
884                 }
885         }
886
887         D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x\n", jeb->offset,
888                   jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size));
889
890         /* mark_node_obsolete can add to wasted !! */
891         if (jeb->wasted_size) {
892                 jeb->dirty_size += jeb->wasted_size;
893                 c->dirty_size += jeb->wasted_size;
894                 c->wasted_size -= jeb->wasted_size;
895                 jeb->wasted_size = 0;
896         }
897
898         return jffs2_scan_classify_jeb(c, jeb);
899 }
900
901 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
902 {
903         struct jffs2_inode_cache *ic;
904
905         ic = jffs2_get_ino_cache(c, ino);
906         if (ic)
907                 return ic;
908
909         if (ino > c->highest_ino)
910                 c->highest_ino = ino;
911
912         ic = jffs2_alloc_inode_cache();
913         if (!ic) {
914                 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n");
915                 return NULL;
916         }
917         memset(ic, 0, sizeof(*ic));
918
919         ic->ino = ino;
920         ic->nodes = (void *)ic;
921         jffs2_add_ino_cache(c, ic);
922         if (ino == 1)
923                 ic->nlink = 1;
924         return ic;
925 }
926
927 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
928                                  struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
929 {
930         struct jffs2_raw_node_ref *raw;
931         struct jffs2_inode_cache *ic;
932         uint32_t ino = je32_to_cpu(ri->ino);
933
934         D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs));
935
936         /* We do very little here now. Just check the ino# to which we should attribute
937            this node; we can do all the CRC checking etc. later. There's a tradeoff here --
938            we used to scan the flash once only, reading everything we want from it into
939            memory, then building all our in-core data structures and freeing the extra
940            information. Now we allow the first part of the mount to complete a lot quicker,
941            but we have to go _back_ to the flash in order to finish the CRC checking, etc.
942            Which means that the _full_ amount of time to get to proper write mode with GC
943            operational may actually be _longer_ than before. Sucks to be me. */
944
945         raw = jffs2_alloc_raw_node_ref();
946         if (!raw) {
947                 printk(KERN_NOTICE "jffs2_scan_inode_node(): allocation of node reference failed\n");
948                 return -ENOMEM;
949         }
950
951         ic = jffs2_get_ino_cache(c, ino);
952         if (!ic) {
953                 /* Inocache get failed. Either we read a bogus ino# or it's just genuinely the
954                    first node we found for this inode. Do a CRC check to protect against the former
955                    case */
956                 uint32_t crc = crc32(0, ri, sizeof(*ri)-8);
957
958                 if (crc != je32_to_cpu(ri->node_crc)) {
959                         printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
960                                ofs, je32_to_cpu(ri->node_crc), crc);
961                         /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
962                         DIRTY_SPACE(PAD(je32_to_cpu(ri->totlen)));
963                         jffs2_free_raw_node_ref(raw);
964                         return 0;
965                 }
966                 ic = jffs2_scan_make_ino_cache(c, ino);
967                 if (!ic) {
968                         jffs2_free_raw_node_ref(raw);
969                         return -ENOMEM;
970                 }
971         }
972
973         /* Wheee. It worked */
974
975         raw->flash_offset = ofs | REF_UNCHECKED;
976
977         raw->next_in_ino = ic->nodes;
978         ic->nodes = raw;
979         
980         jffs2_link_node_ref(c, jeb, raw, PAD(je32_to_cpu(ri->totlen)));
981
982         D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
983                   je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
984                   je32_to_cpu(ri->offset),
985                   je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)));
986
987         pseudo_random += je32_to_cpu(ri->version);
988
989         if (jffs2_sum_active()) {
990                 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
991         }
992
993         return 0;
994 }
995
996 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
997                                   struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
998 {
999         struct jffs2_raw_node_ref *raw;
1000         struct jffs2_full_dirent *fd;
1001         struct jffs2_inode_cache *ic;
1002         uint32_t crc;
1003
1004         D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs));
1005
1006         /* We don't get here unless the node is still valid, so we don't have to
1007            mask in the ACCURATE bit any more. */
1008         crc = crc32(0, rd, sizeof(*rd)-8);
1009
1010         if (crc != je32_to_cpu(rd->node_crc)) {
1011                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1012                        ofs, je32_to_cpu(rd->node_crc), crc);
1013                 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1014                 DIRTY_SPACE(PAD(je32_to_cpu(rd->totlen)));
1015                 return 0;
1016         }
1017
1018         pseudo_random += je32_to_cpu(rd->version);
1019
1020         fd = jffs2_alloc_full_dirent(rd->nsize+1);
1021         if (!fd) {
1022                 return -ENOMEM;
1023         }
1024         memcpy(&fd->name, rd->name, rd->nsize);
1025         fd->name[rd->nsize] = 0;
1026
1027         crc = crc32(0, fd->name, rd->nsize);
1028         if (crc != je32_to_cpu(rd->name_crc)) {
1029                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1030                        ofs, je32_to_cpu(rd->name_crc), crc);
1031                 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino)));
1032                 jffs2_free_full_dirent(fd);
1033                 /* FIXME: Why do we believe totlen? */
1034                 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1035                 DIRTY_SPACE(PAD(je32_to_cpu(rd->totlen)));
1036                 return 0;
1037         }
1038         raw = jffs2_alloc_raw_node_ref();
1039         if (!raw) {
1040                 jffs2_free_full_dirent(fd);
1041                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): allocation of node reference failed\n");
1042                 return -ENOMEM;
1043         }
1044         ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1045         if (!ic) {
1046                 jffs2_free_full_dirent(fd);
1047                 jffs2_free_raw_node_ref(raw);
1048                 return -ENOMEM;
1049         }
1050
1051         raw->flash_offset = ofs | REF_PRISTINE;
1052         raw->next_in_ino = ic->nodes;
1053         ic->nodes = raw;
1054
1055         jffs2_link_node_ref(c, jeb, raw, PAD(je32_to_cpu(rd->totlen)));
1056
1057         fd->raw = raw;
1058         fd->next = NULL;
1059         fd->version = je32_to_cpu(rd->version);
1060         fd->ino = je32_to_cpu(rd->ino);
1061         fd->nhash = full_name_hash(fd->name, rd->nsize);
1062         fd->type = rd->type;
1063         jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1064
1065         if (jffs2_sum_active()) {
1066                 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1067         }
1068
1069         return 0;
1070 }
1071
1072 static int count_list(struct list_head *l)
1073 {
1074         uint32_t count = 0;
1075         struct list_head *tmp;
1076
1077         list_for_each(tmp, l) {
1078                 count++;
1079         }
1080         return count;
1081 }
1082
1083 /* Note: This breaks if list_empty(head). I don't care. You
1084    might, if you copy this code and use it elsewhere :) */
1085 static void rotate_list(struct list_head *head, uint32_t count)
1086 {
1087         struct list_head *n = head->next;
1088
1089         list_del(head);
1090         while(count--) {
1091                 n = n->next;
1092         }
1093         list_add(head, n);
1094 }
1095
1096 void jffs2_rotate_lists(struct jffs2_sb_info *c)
1097 {
1098         uint32_t x;
1099         uint32_t rotateby;
1100
1101         x = count_list(&c->clean_list);
1102         if (x) {
1103                 rotateby = pseudo_random % x;
1104                 rotate_list((&c->clean_list), rotateby);
1105         }
1106
1107         x = count_list(&c->very_dirty_list);
1108         if (x) {
1109                 rotateby = pseudo_random % x;
1110                 rotate_list((&c->very_dirty_list), rotateby);
1111         }
1112
1113         x = count_list(&c->dirty_list);
1114         if (x) {
1115                 rotateby = pseudo_random % x;
1116                 rotate_list((&c->dirty_list), rotateby);
1117         }
1118
1119         x = count_list(&c->erasable_list);
1120         if (x) {
1121                 rotateby = pseudo_random % x;
1122                 rotate_list((&c->erasable_list), rotateby);
1123         }
1124
1125         if (c->nr_erasing_blocks) {
1126                 rotateby = pseudo_random % c->nr_erasing_blocks;
1127                 rotate_list((&c->erase_pending_list), rotateby);
1128         }
1129
1130         if (c->nr_free_blocks) {
1131                 rotateby = pseudo_random % c->nr_free_blocks;
1132                 rotate_list((&c->free_list), rotateby);
1133         }
1134 }