[JFFS2] Deletion dirents should be REF_NORMAL, not REF_PRISTINE.
[linux-2.6.git] / fs / jffs2 / scan.c
1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright © 2001-2007 Red Hat, Inc.
5  *
6  * Created by David Woodhouse <dwmw2@infradead.org>
7  *
8  * For licensing information, see the file 'LICENCE' in this directory.
9  *
10  */
11
12 #include <linux/kernel.h>
13 #include <linux/sched.h>
14 #include <linux/slab.h>
15 #include <linux/mtd/mtd.h>
16 #include <linux/pagemap.h>
17 #include <linux/crc32.h>
18 #include <linux/compiler.h>
19 #include "nodelist.h"
20 #include "summary.h"
21 #include "debug.h"
22
23 #define DEFAULT_EMPTY_SCAN_SIZE 1024
24
25 #define noisy_printk(noise, args...) do { \
26         if (*(noise)) { \
27                 printk(KERN_NOTICE args); \
28                  (*(noise))--; \
29                  if (!(*(noise))) { \
30                          printk(KERN_NOTICE "Further such events for this erase block will not be printed\n"); \
31                  } \
32         } \
33 } while(0)
34
35 static uint32_t pseudo_random;
36
37 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
38                                   unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s);
39
40 /* These helper functions _must_ increase ofs and also do the dirty/used space accounting.
41  * Returning an error will abort the mount - bad checksums etc. should just mark the space
42  * as dirty.
43  */
44 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
45                                  struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s);
46 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
47                                  struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s);
48
49 static inline int min_free(struct jffs2_sb_info *c)
50 {
51         uint32_t min = 2 * sizeof(struct jffs2_raw_inode);
52 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
53         if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize)
54                 return c->wbuf_pagesize;
55 #endif
56         return min;
57
58 }
59
60 static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) {
61         if (sector_size < DEFAULT_EMPTY_SCAN_SIZE)
62                 return sector_size;
63         else
64                 return DEFAULT_EMPTY_SCAN_SIZE;
65 }
66
67 static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
68 {
69         int ret;
70
71         if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
72                 return ret;
73         if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size)))
74                 return ret;
75         /* Turned wasted size into dirty, since we apparently 
76            think it's recoverable now. */
77         jeb->dirty_size += jeb->wasted_size;
78         c->dirty_size += jeb->wasted_size;
79         c->wasted_size -= jeb->wasted_size;
80         jeb->wasted_size = 0;
81         if (VERYDIRTY(c, jeb->dirty_size)) {
82                 list_add(&jeb->list, &c->very_dirty_list);
83         } else {
84                 list_add(&jeb->list, &c->dirty_list);
85         }
86         return 0;
87 }
88
89 int jffs2_scan_medium(struct jffs2_sb_info *c)
90 {
91         int i, ret;
92         uint32_t empty_blocks = 0, bad_blocks = 0;
93         unsigned char *flashbuf = NULL;
94         uint32_t buf_size = 0;
95         struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
96 #ifndef __ECOS
97         size_t pointlen;
98
99         if (c->mtd->point) {
100                 ret = c->mtd->point (c->mtd, 0, c->mtd->size, &pointlen, &flashbuf);
101                 if (!ret && pointlen < c->mtd->size) {
102                         /* Don't muck about if it won't let us point to the whole flash */
103                         D1(printk(KERN_DEBUG "MTD point returned len too short: 0x%zx\n", pointlen));
104                         c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size);
105                         flashbuf = NULL;
106                 }
107                 if (ret)
108                         D1(printk(KERN_DEBUG "MTD point failed %d\n", ret));
109         }
110 #endif
111         if (!flashbuf) {
112                 /* For NAND it's quicker to read a whole eraseblock at a time,
113                    apparently */
114                 if (jffs2_cleanmarker_oob(c))
115                         buf_size = c->sector_size;
116                 else
117                         buf_size = PAGE_SIZE;
118
119                 /* Respect kmalloc limitations */
120                 if (buf_size > 128*1024)
121                         buf_size = 128*1024;
122
123                 D1(printk(KERN_DEBUG "Allocating readbuf of %d bytes\n", buf_size));
124                 flashbuf = kmalloc(buf_size, GFP_KERNEL);
125                 if (!flashbuf)
126                         return -ENOMEM;
127         }
128
129         if (jffs2_sum_active()) {
130                 s = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL);
131                 if (!s) {
132                         kfree(flashbuf);
133                         JFFS2_WARNING("Can't allocate memory for summary\n");
134                         return -ENOMEM;
135                 }
136         }
137
138         for (i=0; i<c->nr_blocks; i++) {
139                 struct jffs2_eraseblock *jeb = &c->blocks[i];
140
141                 cond_resched();
142
143                 /* reset summary info for next eraseblock scan */
144                 jffs2_sum_reset_collected(s);
145
146                 ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
147                                                 buf_size, s);
148
149                 if (ret < 0)
150                         goto out;
151
152                 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
153
154                 /* Now decide which list to put it on */
155                 switch(ret) {
156                 case BLK_STATE_ALLFF:
157                         /*
158                          * Empty block.   Since we can't be sure it
159                          * was entirely erased, we just queue it for erase
160                          * again.  It will be marked as such when the erase
161                          * is complete.  Meanwhile we still count it as empty
162                          * for later checks.
163                          */
164                         empty_blocks++;
165                         list_add(&jeb->list, &c->erase_pending_list);
166                         c->nr_erasing_blocks++;
167                         break;
168
169                 case BLK_STATE_CLEANMARKER:
170                         /* Only a CLEANMARKER node is valid */
171                         if (!jeb->dirty_size) {
172                                 /* It's actually free */
173                                 list_add(&jeb->list, &c->free_list);
174                                 c->nr_free_blocks++;
175                         } else {
176                                 /* Dirt */
177                                 D1(printk(KERN_DEBUG "Adding all-dirty block at 0x%08x to erase_pending_list\n", jeb->offset));
178                                 list_add(&jeb->list, &c->erase_pending_list);
179                                 c->nr_erasing_blocks++;
180                         }
181                         break;
182
183                 case BLK_STATE_CLEAN:
184                         /* Full (or almost full) of clean data. Clean list */
185                         list_add(&jeb->list, &c->clean_list);
186                         break;
187
188                 case BLK_STATE_PARTDIRTY:
189                         /* Some data, but not full. Dirty list. */
190                         /* We want to remember the block with most free space
191                         and stick it in the 'nextblock' position to start writing to it. */
192                         if (jeb->free_size > min_free(c) &&
193                                         (!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
194                                 /* Better candidate for the next writes to go to */
195                                 if (c->nextblock) {
196                                         ret = file_dirty(c, c->nextblock);
197                                         if (ret)
198                                                 return ret;
199                                         /* deleting summary information of the old nextblock */
200                                         jffs2_sum_reset_collected(c->summary);
201                                 }
202                                 /* update collected summary information for the current nextblock */
203                                 jffs2_sum_move_collected(c, s);
204                                 D1(printk(KERN_DEBUG "jffs2_scan_medium(): new nextblock = 0x%08x\n", jeb->offset));
205                                 c->nextblock = jeb;
206                         } else {
207                                 ret = file_dirty(c, jeb);
208                                 if (ret)
209                                         return ret;
210                         }
211                         break;
212
213                 case BLK_STATE_ALLDIRTY:
214                         /* Nothing valid - not even a clean marker. Needs erasing. */
215                         /* For now we just put it on the erasing list. We'll start the erases later */
216                         D1(printk(KERN_NOTICE "JFFS2: Erase block at 0x%08x is not formatted. It will be erased\n", jeb->offset));
217                         list_add(&jeb->list, &c->erase_pending_list);
218                         c->nr_erasing_blocks++;
219                         break;
220
221                 case BLK_STATE_BADBLOCK:
222                         D1(printk(KERN_NOTICE "JFFS2: Block at 0x%08x is bad\n", jeb->offset));
223                         list_add(&jeb->list, &c->bad_list);
224                         c->bad_size += c->sector_size;
225                         c->free_size -= c->sector_size;
226                         bad_blocks++;
227                         break;
228                 default:
229                         printk(KERN_WARNING "jffs2_scan_medium(): unknown block state\n");
230                         BUG();
231                 }
232         }
233
234         /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
235         if (c->nextblock && (c->nextblock->dirty_size)) {
236                 c->nextblock->wasted_size += c->nextblock->dirty_size;
237                 c->wasted_size += c->nextblock->dirty_size;
238                 c->dirty_size -= c->nextblock->dirty_size;
239                 c->nextblock->dirty_size = 0;
240         }
241 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
242         if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) {
243                 /* If we're going to start writing into a block which already
244                    contains data, and the end of the data isn't page-aligned,
245                    skip a little and align it. */
246
247                 uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize;
248
249                 D1(printk(KERN_DEBUG "jffs2_scan_medium(): Skipping %d bytes in nextblock to ensure page alignment\n",
250                           skip));
251                 jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
252                 jffs2_scan_dirty_space(c, c->nextblock, skip);
253         }
254 #endif
255         if (c->nr_erasing_blocks) {
256                 if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) {
257                         printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
258                         printk(KERN_NOTICE "empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",empty_blocks,bad_blocks,c->nr_blocks);
259                         ret = -EIO;
260                         goto out;
261                 }
262                 jffs2_erase_pending_trigger(c);
263         }
264         ret = 0;
265  out:
266         if (buf_size)
267                 kfree(flashbuf);
268 #ifndef __ECOS
269         else
270                 c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size);
271 #endif
272         if (s)
273                 kfree(s);
274
275         return ret;
276 }
277
278 static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf,
279                                uint32_t ofs, uint32_t len)
280 {
281         int ret;
282         size_t retlen;
283
284         ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
285         if (ret) {
286                 D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", len, ofs, ret));
287                 return ret;
288         }
289         if (retlen < len) {
290                 D1(printk(KERN_WARNING "Read at 0x%x gave only 0x%zx bytes\n", ofs, retlen));
291                 return -EIO;
292         }
293         return 0;
294 }
295
296 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
297 {
298         if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
299             && (!jeb->first_node || !ref_next(jeb->first_node)) )
300                 return BLK_STATE_CLEANMARKER;
301
302         /* move blocks with max 4 byte dirty space to cleanlist */
303         else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
304                 c->dirty_size -= jeb->dirty_size;
305                 c->wasted_size += jeb->dirty_size;
306                 jeb->wasted_size += jeb->dirty_size;
307                 jeb->dirty_size = 0;
308                 return BLK_STATE_CLEAN;
309         } else if (jeb->used_size || jeb->unchecked_size)
310                 return BLK_STATE_PARTDIRTY;
311         else
312                 return BLK_STATE_ALLDIRTY;
313 }
314
315 #ifdef CONFIG_JFFS2_FS_XATTR
316 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
317                                  struct jffs2_raw_xattr *rx, uint32_t ofs,
318                                  struct jffs2_summary *s)
319 {
320         struct jffs2_xattr_datum *xd;
321         uint32_t xid, version, totlen, crc;
322         int err;
323
324         crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
325         if (crc != je32_to_cpu(rx->node_crc)) {
326                 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
327                               ofs, je32_to_cpu(rx->node_crc), crc);
328                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
329                         return err;
330                 return 0;
331         }
332
333         xid = je32_to_cpu(rx->xid);
334         version = je32_to_cpu(rx->version);
335
336         totlen = PAD(sizeof(struct jffs2_raw_xattr)
337                         + rx->name_len + 1 + je16_to_cpu(rx->value_len));
338         if (totlen != je32_to_cpu(rx->totlen)) {
339                 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
340                               ofs, je32_to_cpu(rx->totlen), totlen);
341                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
342                         return err;
343                 return 0;
344         }
345
346         xd = jffs2_setup_xattr_datum(c, xid, version);
347         if (IS_ERR(xd))
348                 return PTR_ERR(xd);
349
350         if (xd->version > version) {
351                 struct jffs2_raw_node_ref *raw
352                         = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL);
353                 raw->next_in_ino = xd->node->next_in_ino;
354                 xd->node->next_in_ino = raw;
355         } else {
356                 xd->version = version;
357                 xd->xprefix = rx->xprefix;
358                 xd->name_len = rx->name_len;
359                 xd->value_len = je16_to_cpu(rx->value_len);
360                 xd->data_crc = je32_to_cpu(rx->data_crc);
361
362                 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd);
363         }
364
365         if (jffs2_sum_active())
366                 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
367         dbg_xattr("scaning xdatum at %#08x (xid=%u, version=%u)\n",
368                   ofs, xd->xid, xd->version);
369         return 0;
370 }
371
372 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
373                                 struct jffs2_raw_xref *rr, uint32_t ofs,
374                                 struct jffs2_summary *s)
375 {
376         struct jffs2_xattr_ref *ref;
377         uint32_t crc;
378         int err;
379
380         crc = crc32(0, rr, sizeof(*rr) - 4);
381         if (crc != je32_to_cpu(rr->node_crc)) {
382                 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
383                               ofs, je32_to_cpu(rr->node_crc), crc);
384                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
385                         return err;
386                 return 0;
387         }
388
389         if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
390                 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n",
391                               ofs, je32_to_cpu(rr->totlen),
392                               PAD(sizeof(struct jffs2_raw_xref)));
393                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
394                         return err;
395                 return 0;
396         }
397
398         ref = jffs2_alloc_xattr_ref();
399         if (!ref)
400                 return -ENOMEM;
401
402         /* BEFORE jffs2_build_xattr_subsystem() called, 
403          * and AFTER xattr_ref is marked as a dead xref,
404          * ref->xid is used to store 32bit xid, xd is not used
405          * ref->ino is used to store 32bit inode-number, ic is not used
406          * Thoes variables are declared as union, thus using those
407          * are exclusive. In a similar way, ref->next is temporarily
408          * used to chain all xattr_ref object. It's re-chained to
409          * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
410          */
411         ref->ino = je32_to_cpu(rr->ino);
412         ref->xid = je32_to_cpu(rr->xid);
413         ref->xseqno = je32_to_cpu(rr->xseqno);
414         if (ref->xseqno > c->highest_xseqno)
415                 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
416         ref->next = c->xref_temp;
417         c->xref_temp = ref;
418
419         jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref);
420
421         if (jffs2_sum_active())
422                 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
423         dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
424                   ofs, ref->xid, ref->ino);
425         return 0;
426 }
427 #endif
428
429 /* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
430    the flash, XIP-style */
431 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
432                                   unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
433         struct jffs2_unknown_node *node;
434         struct jffs2_unknown_node crcnode;
435         uint32_t ofs, prevofs;
436         uint32_t hdr_crc, buf_ofs, buf_len;
437         int err;
438         int noise = 0;
439
440
441 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
442         int cleanmarkerfound = 0;
443 #endif
444
445         ofs = jeb->offset;
446         prevofs = jeb->offset - 1;
447
448         D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs));
449
450 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
451         if (jffs2_cleanmarker_oob(c)) {
452                 int ret;
453
454                 if (c->mtd->block_isbad(c->mtd, jeb->offset))
455                         return BLK_STATE_BADBLOCK;
456
457                 ret = jffs2_check_nand_cleanmarker(c, jeb);
458                 D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret));
459
460                 /* Even if it's not found, we still scan to see
461                    if the block is empty. We use this information
462                    to decide whether to erase it or not. */
463                 switch (ret) {
464                 case 0:         cleanmarkerfound = 1; break;
465                 case 1:         break;
466                 default:        return ret;
467                 }
468         }
469 #endif
470
471         if (jffs2_sum_active()) {
472                 struct jffs2_sum_marker *sm;
473                 void *sumptr = NULL;
474                 uint32_t sumlen;
475               
476                 if (!buf_size) {
477                         /* XIP case. Just look, point at the summary if it's there */
478                         sm = (void *)buf + c->sector_size - sizeof(*sm);
479                         if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
480                                 sumptr = buf + je32_to_cpu(sm->offset);
481                                 sumlen = c->sector_size - je32_to_cpu(sm->offset);
482                         }
483                 } else {
484                         /* If NAND flash, read a whole page of it. Else just the end */
485                         if (c->wbuf_pagesize)
486                                 buf_len = c->wbuf_pagesize;
487                         else
488                                 buf_len = sizeof(*sm);
489
490                         /* Read as much as we want into the _end_ of the preallocated buffer */
491                         err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, 
492                                                   jeb->offset + c->sector_size - buf_len,
493                                                   buf_len);                             
494                         if (err)
495                                 return err;
496
497                         sm = (void *)buf + buf_size - sizeof(*sm);
498                         if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
499                                 sumlen = c->sector_size - je32_to_cpu(sm->offset);
500                                 sumptr = buf + buf_size - sumlen;
501
502                                 /* Now, make sure the summary itself is available */
503                                 if (sumlen > buf_size) {
504                                         /* Need to kmalloc for this. */
505                                         sumptr = kmalloc(sumlen, GFP_KERNEL);
506                                         if (!sumptr)
507                                                 return -ENOMEM;
508                                         memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
509                                 }
510                                 if (buf_len < sumlen) {
511                                         /* Need to read more so that the entire summary node is present */
512                                         err = jffs2_fill_scan_buf(c, sumptr, 
513                                                                   jeb->offset + c->sector_size - sumlen,
514                                                                   sumlen - buf_len);                            
515                                         if (err)
516                                                 return err;
517                                 }
518                         }
519
520                 }
521
522                 if (sumptr) {
523                         err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
524
525                         if (buf_size && sumlen > buf_size)
526                                 kfree(sumptr);
527                         /* If it returns with a real error, bail. 
528                            If it returns positive, that's a block classification
529                            (i.e. BLK_STATE_xxx) so return that too.
530                            If it returns zero, fall through to full scan. */
531                         if (err)
532                                 return err;
533                 }
534         }
535
536         buf_ofs = jeb->offset;
537
538         if (!buf_size) {
539                 /* This is the XIP case -- we're reading _directly_ from the flash chip */
540                 buf_len = c->sector_size;
541         } else {
542                 buf_len = EMPTY_SCAN_SIZE(c->sector_size);
543                 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
544                 if (err)
545                         return err;
546         }
547
548         /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
549         ofs = 0;
550
551         /* Scan only 4KiB of 0xFF before declaring it's empty */
552         while(ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
553                 ofs += 4;
554
555         if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) {
556 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
557                 if (jffs2_cleanmarker_oob(c)) {
558                         /* scan oob, take care of cleanmarker */
559                         int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
560                         D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret));
561                         switch (ret) {
562                         case 0:         return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
563                         case 1:         return BLK_STATE_ALLDIRTY;
564                         default:        return ret;
565                         }
566                 }
567 #endif
568                 D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset));
569                 if (c->cleanmarker_size == 0)
570                         return BLK_STATE_CLEANMARKER;   /* don't bother with re-erase */
571                 else
572                         return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
573         }
574         if (ofs) {
575                 D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset,
576                           jeb->offset + ofs));
577                 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
578                         return err;
579                 if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
580                         return err;
581         }
582
583         /* Now ofs is a complete physical flash offset as it always was... */
584         ofs += jeb->offset;
585
586         noise = 10;
587
588         dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
589
590 scan_more:
591         while(ofs < jeb->offset + c->sector_size) {
592
593                 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
594
595                 /* Make sure there are node refs available for use */
596                 err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
597                 if (err)
598                         return err;
599
600                 cond_resched();
601
602                 if (ofs & 3) {
603                         printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs);
604                         ofs = PAD(ofs);
605                         continue;
606                 }
607                 if (ofs == prevofs) {
608                         printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs);
609                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
610                                 return err;
611                         ofs += 4;
612                         continue;
613                 }
614                 prevofs = ofs;
615
616                 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
617                         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),
618                                   jeb->offset, c->sector_size, ofs, sizeof(*node)));
619                         if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
620                                 return err;
621                         break;
622                 }
623
624                 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
625                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
626                         D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
627                                   sizeof(struct jffs2_unknown_node), buf_len, ofs));
628                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
629                         if (err)
630                                 return err;
631                         buf_ofs = ofs;
632                 }
633
634                 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
635
636                 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
637                         uint32_t inbuf_ofs;
638                         uint32_t empty_start, scan_end;
639
640                         empty_start = ofs;
641                         ofs += 4;
642                         scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len);
643
644                         D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs));
645                 more_empty:
646                         inbuf_ofs = ofs - buf_ofs;
647                         while (inbuf_ofs < scan_end) {
648                                 if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) {
649                                         printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n",
650                                                empty_start, ofs);
651                                         if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
652                                                 return err;
653                                         goto scan_more;
654                                 }
655
656                                 inbuf_ofs+=4;
657                                 ofs += 4;
658                         }
659                         /* Ran off end. */
660                         D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs));
661
662                         /* If we're only checking the beginning of a block with a cleanmarker,
663                            bail now */
664                         if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
665                             c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
666                                 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size)));
667                                 return BLK_STATE_CLEANMARKER;
668                         }
669                         if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */
670                                 scan_end = buf_len;
671                                 goto more_empty;
672                         }
673                         
674                         /* See how much more there is to read in this eraseblock... */
675                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
676                         if (!buf_len) {
677                                 /* No more to read. Break out of main loop without marking
678                                    this range of empty space as dirty (because it's not) */
679                                 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n",
680                                           empty_start));
681                                 break;
682                         }
683                         /* point never reaches here */
684                         scan_end = buf_len;
685                         D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs));
686                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
687                         if (err)
688                                 return err;
689                         buf_ofs = ofs;
690                         goto more_empty;
691                 }
692
693                 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
694                         printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs);
695                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
696                                 return err;
697                         ofs += 4;
698                         continue;
699                 }
700                 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
701                         D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs));
702                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
703                                 return err;
704                         ofs += 4;
705                         continue;
706                 }
707                 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
708                         printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs);
709                         printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n");
710                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
711                                 return err;
712                         ofs += 4;
713                         continue;
714                 }
715                 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
716                         /* OK. We're out of possibilities. Whinge and move on */
717                         noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
718                                      JFFS2_MAGIC_BITMASK, ofs,
719                                      je16_to_cpu(node->magic));
720                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
721                                 return err;
722                         ofs += 4;
723                         continue;
724                 }
725                 /* We seem to have a node of sorts. Check the CRC */
726                 crcnode.magic = node->magic;
727                 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
728                 crcnode.totlen = node->totlen;
729                 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
730
731                 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
732                         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",
733                                      ofs, je16_to_cpu(node->magic),
734                                      je16_to_cpu(node->nodetype),
735                                      je32_to_cpu(node->totlen),
736                                      je32_to_cpu(node->hdr_crc),
737                                      hdr_crc);
738                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
739                                 return err;
740                         ofs += 4;
741                         continue;
742                 }
743
744                 if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) {
745                         /* Eep. Node goes over the end of the erase block. */
746                         printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
747                                ofs, je32_to_cpu(node->totlen));
748                         printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
749                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
750                                 return err;
751                         ofs += 4;
752                         continue;
753                 }
754
755                 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
756                         /* Wheee. This is an obsoleted node */
757                         D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));
758                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
759                                 return err;
760                         ofs += PAD(je32_to_cpu(node->totlen));
761                         continue;
762                 }
763
764                 switch(je16_to_cpu(node->nodetype)) {
765                 case JFFS2_NODETYPE_INODE:
766                         if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
767                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
768                                 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
769                                           sizeof(struct jffs2_raw_inode), 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_inode_node(c, jeb, (void *)node, ofs, s);
777                         if (err) return err;
778                         ofs += PAD(je32_to_cpu(node->totlen));
779                         break;
780
781                 case JFFS2_NODETYPE_DIRENT:
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 (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
785                                           je32_to_cpu(node->totlen), buf_len, ofs));
786                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
787                                 if (err)
788                                         return err;
789                                 buf_ofs = ofs;
790                                 node = (void *)buf;
791                         }
792                         err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
793                         if (err) return err;
794                         ofs += PAD(je32_to_cpu(node->totlen));
795                         break;
796
797 #ifdef CONFIG_JFFS2_FS_XATTR
798                 case JFFS2_NODETYPE_XATTR:
799                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
800                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
801                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)"
802                                           " left to end of buf. Reading 0x%x at 0x%08x\n",
803                                           je32_to_cpu(node->totlen), buf_len, ofs));
804                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
805                                 if (err)
806                                         return err;
807                                 buf_ofs = ofs;
808                                 node = (void *)buf;
809                         }
810                         err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
811                         if (err)
812                                 return err;
813                         ofs += PAD(je32_to_cpu(node->totlen));
814                         break;
815                 case JFFS2_NODETYPE_XREF:
816                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
817                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
818                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)"
819                                           " left to end of buf. Reading 0x%x at 0x%08x\n",
820                                           je32_to_cpu(node->totlen), buf_len, ofs));
821                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
822                                 if (err)
823                                         return err;
824                                 buf_ofs = ofs;
825                                 node = (void *)buf;
826                         }
827                         err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
828                         if (err)
829                                 return err;
830                         ofs += PAD(je32_to_cpu(node->totlen));
831                         break;
832 #endif  /* CONFIG_JFFS2_FS_XATTR */
833
834                 case JFFS2_NODETYPE_CLEANMARKER:
835                         D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs));
836                         if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
837                                 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
838                                        ofs, je32_to_cpu(node->totlen), c->cleanmarker_size);
839                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
840                                         return err;
841                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
842                         } else if (jeb->first_node) {
843                                 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset);
844                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
845                                         return err;
846                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
847                         } else {
848                                 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
849
850                                 ofs += PAD(c->cleanmarker_size);
851                         }
852                         break;
853
854                 case JFFS2_NODETYPE_PADDING:
855                         if (jffs2_sum_active())
856                                 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
857                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
858                                 return err;
859                         ofs += PAD(je32_to_cpu(node->totlen));
860                         break;
861
862                 default:
863                         switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
864                         case JFFS2_FEATURE_ROCOMPAT:
865                                 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
866                                 c->flags |= JFFS2_SB_FLAG_RO;
867                                 if (!(jffs2_is_readonly(c)))
868                                         return -EROFS;
869                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
870                                         return err;
871                                 ofs += PAD(je32_to_cpu(node->totlen));
872                                 break;
873
874                         case JFFS2_FEATURE_INCOMPAT:
875                                 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
876                                 return -EINVAL;
877
878                         case JFFS2_FEATURE_RWCOMPAT_DELETE:
879                                 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
880                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
881                                         return err;
882                                 ofs += PAD(je32_to_cpu(node->totlen));
883                                 break;
884
885                         case JFFS2_FEATURE_RWCOMPAT_COPY: {
886                                 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
887
888                                 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
889
890                                 /* We can't summarise nodes we don't grok */
891                                 jffs2_sum_disable_collecting(s);
892                                 ofs += PAD(je32_to_cpu(node->totlen));
893                                 break;
894                                 }
895                         }
896                 }
897         }
898
899         if (jffs2_sum_active()) {
900                 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
901                         dbg_summary("There is not enough space for "
902                                 "summary information, disabling for this jeb!\n");
903                         jffs2_sum_disable_collecting(s);
904                 }
905         }
906
907         D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
908                   jeb->offset,jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size, jeb->wasted_size));
909         
910         /* mark_node_obsolete can add to wasted !! */
911         if (jeb->wasted_size) {
912                 jeb->dirty_size += jeb->wasted_size;
913                 c->dirty_size += jeb->wasted_size;
914                 c->wasted_size -= jeb->wasted_size;
915                 jeb->wasted_size = 0;
916         }
917
918         return jffs2_scan_classify_jeb(c, jeb);
919 }
920
921 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
922 {
923         struct jffs2_inode_cache *ic;
924
925         ic = jffs2_get_ino_cache(c, ino);
926         if (ic)
927                 return ic;
928
929         if (ino > c->highest_ino)
930                 c->highest_ino = ino;
931
932         ic = jffs2_alloc_inode_cache();
933         if (!ic) {
934                 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n");
935                 return NULL;
936         }
937         memset(ic, 0, sizeof(*ic));
938
939         ic->ino = ino;
940         ic->nodes = (void *)ic;
941         jffs2_add_ino_cache(c, ic);
942         if (ino == 1)
943                 ic->nlink = 1;
944         return ic;
945 }
946
947 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
948                                  struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
949 {
950         struct jffs2_inode_cache *ic;
951         uint32_t crc, ino = je32_to_cpu(ri->ino);
952
953         D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs));
954
955         /* We do very little here now. Just check the ino# to which we should attribute
956            this node; we can do all the CRC checking etc. later. There's a tradeoff here --
957            we used to scan the flash once only, reading everything we want from it into
958            memory, then building all our in-core data structures and freeing the extra
959            information. Now we allow the first part of the mount to complete a lot quicker,
960            but we have to go _back_ to the flash in order to finish the CRC checking, etc.
961            Which means that the _full_ amount of time to get to proper write mode with GC
962            operational may actually be _longer_ than before. Sucks to be me. */
963
964         /* Check the node CRC in any case. */
965         crc = crc32(0, ri, sizeof(*ri)-8);
966         if (crc != je32_to_cpu(ri->node_crc)) {
967                 printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on "
968                        "node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
969                        ofs, je32_to_cpu(ri->node_crc), crc);
970                 /*
971                  * We believe totlen because the CRC on the node
972                  * _header_ was OK, just the node itself failed.
973                  */
974                 return jffs2_scan_dirty_space(c, jeb,
975                                               PAD(je32_to_cpu(ri->totlen)));
976         }
977
978         ic = jffs2_get_ino_cache(c, ino);
979         if (!ic) {
980                 ic = jffs2_scan_make_ino_cache(c, ino);
981                 if (!ic)
982                         return -ENOMEM;
983         }
984
985         /* Wheee. It worked */
986         jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
987
988         D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
989                   je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
990                   je32_to_cpu(ri->offset),
991                   je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)));
992
993         pseudo_random += je32_to_cpu(ri->version);
994
995         if (jffs2_sum_active()) {
996                 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
997         }
998
999         return 0;
1000 }
1001
1002 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
1003                                   struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
1004 {
1005         struct jffs2_full_dirent *fd;
1006         struct jffs2_inode_cache *ic;
1007         uint32_t crc;
1008         int err;
1009
1010         D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs));
1011
1012         /* We don't get here unless the node is still valid, so we don't have to
1013            mask in the ACCURATE bit any more. */
1014         crc = crc32(0, rd, sizeof(*rd)-8);
1015
1016         if (crc != je32_to_cpu(rd->node_crc)) {
1017                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1018                        ofs, je32_to_cpu(rd->node_crc), crc);
1019                 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1020                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1021                         return err;
1022                 return 0;
1023         }
1024
1025         pseudo_random += je32_to_cpu(rd->version);
1026
1027         fd = jffs2_alloc_full_dirent(rd->nsize+1);
1028         if (!fd) {
1029                 return -ENOMEM;
1030         }
1031         memcpy(&fd->name, rd->name, rd->nsize);
1032         fd->name[rd->nsize] = 0;
1033
1034         crc = crc32(0, fd->name, rd->nsize);
1035         if (crc != je32_to_cpu(rd->name_crc)) {
1036                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1037                        ofs, je32_to_cpu(rd->name_crc), crc);
1038                 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino)));
1039                 jffs2_free_full_dirent(fd);
1040                 /* FIXME: Why do we believe totlen? */
1041                 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1042                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1043                         return err;
1044                 return 0;
1045         }
1046         ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1047         if (!ic) {
1048                 jffs2_free_full_dirent(fd);
1049                 return -ENOMEM;
1050         }
1051
1052         fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd),
1053                                       PAD(je32_to_cpu(rd->totlen)), ic);
1054
1055         fd->next = NULL;
1056         fd->version = je32_to_cpu(rd->version);
1057         fd->ino = je32_to_cpu(rd->ino);
1058         fd->nhash = full_name_hash(fd->name, rd->nsize);
1059         fd->type = rd->type;
1060         jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1061
1062         if (jffs2_sum_active()) {
1063                 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1064         }
1065
1066         return 0;
1067 }
1068
1069 static int count_list(struct list_head *l)
1070 {
1071         uint32_t count = 0;
1072         struct list_head *tmp;
1073
1074         list_for_each(tmp, l) {
1075                 count++;
1076         }
1077         return count;
1078 }
1079
1080 /* Note: This breaks if list_empty(head). I don't care. You
1081    might, if you copy this code and use it elsewhere :) */
1082 static void rotate_list(struct list_head *head, uint32_t count)
1083 {
1084         struct list_head *n = head->next;
1085
1086         list_del(head);
1087         while(count--) {
1088                 n = n->next;
1089         }
1090         list_add(head, n);
1091 }
1092
1093 void jffs2_rotate_lists(struct jffs2_sb_info *c)
1094 {
1095         uint32_t x;
1096         uint32_t rotateby;
1097
1098         x = count_list(&c->clean_list);
1099         if (x) {
1100                 rotateby = pseudo_random % x;
1101                 rotate_list((&c->clean_list), rotateby);
1102         }
1103
1104         x = count_list(&c->very_dirty_list);
1105         if (x) {
1106                 rotateby = pseudo_random % x;
1107                 rotate_list((&c->very_dirty_list), rotateby);
1108         }
1109
1110         x = count_list(&c->dirty_list);
1111         if (x) {
1112                 rotateby = pseudo_random % x;
1113                 rotate_list((&c->dirty_list), rotateby);
1114         }
1115
1116         x = count_list(&c->erasable_list);
1117         if (x) {
1118                 rotateby = pseudo_random % x;
1119                 rotate_list((&c->erasable_list), rotateby);
1120         }
1121
1122         if (c->nr_erasing_blocks) {
1123                 rotateby = pseudo_random % c->nr_erasing_blocks;
1124                 rotate_list((&c->erase_pending_list), rotateby);
1125         }
1126
1127         if (c->nr_free_blocks) {
1128                 rotateby = pseudo_random % c->nr_free_blocks;
1129                 rotate_list((&c->free_list), rotateby);
1130         }
1131 }