Merge git://git.infradead.org/jffs2-xattr-2.6
[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->__totlen = totlen;
355         raw->flash_offset = ofs | REF_PRISTINE;
356         raw->next_phys = NULL;
357         raw->next_in_ino = (void *)xd;
358         if (!jeb->first_node)
359                 jeb->first_node = raw;
360         if (jeb->last_node)
361                 jeb->last_node->next_phys = raw;
362         jeb->last_node = raw;
363
364         USED_SPACE(PAD(je32_to_cpu(rx->totlen)));
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         struct jffs2_raw_node_ref *raw;
378         uint32_t crc;
379
380         crc = crc32(0, rr, sizeof(*rr) - 4);
381         if (crc != je32_to_cpu(rr->node_crc)) {
382                 if (je32_to_cpu(rr->node_crc) != 0xffffffff)
383                         JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
384                                       ofs, je32_to_cpu(rr->node_crc), crc);
385                 DIRTY_SPACE(PAD(je32_to_cpu(rr->totlen)));
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=%u\n",
391                               ofs, je32_to_cpu(rr->totlen),
392                               PAD(sizeof(struct jffs2_raw_xref)));
393                 DIRTY_SPACE(je32_to_cpu(rr->totlen));
394                 return 0;
395         }
396
397         ref = jffs2_alloc_xattr_ref();
398         if (!ref)
399                 return -ENOMEM;
400
401         raw =  jffs2_alloc_raw_node_ref();
402         if (!raw) {
403                 jffs2_free_xattr_ref(ref);
404                 return -ENOMEM;
405         }
406
407         /* BEFORE jffs2_build_xattr_subsystem() called, 
408          * ref->xid is used to store 32bit xid, xd is not used
409          * ref->ino is used to store 32bit inode-number, ic is not used
410          * Thoes variables are declared as union, thus using those
411          * are exclusive. In a similar way, ref->next is temporarily
412          * used to chain all xattr_ref object. It's re-chained to
413          * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
414          */
415         ref->node = raw;
416         ref->ino = je32_to_cpu(rr->ino);
417         ref->xid = je32_to_cpu(rr->xid);
418         ref->next = c->xref_temp;
419         c->xref_temp = ref;
420
421         raw->__totlen = PAD(je32_to_cpu(rr->totlen));
422         raw->flash_offset = ofs | REF_PRISTINE;
423         raw->next_phys = NULL;
424         raw->next_in_ino = (void *)ref;
425         if (!jeb->first_node)
426                 jeb->first_node = raw;
427         if (jeb->last_node)
428                 jeb->last_node->next_phys = raw;
429         jeb->last_node = raw;
430
431         USED_SPACE(PAD(je32_to_cpu(rr->totlen)));       
432         if (jffs2_sum_active())
433                 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
434         dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
435                   ofs, ref->xid, ref->ino);
436         return 0;
437 }
438 #endif
439
440 /* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
441    the flash, XIP-style */
442 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
443                                   unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
444         struct jffs2_unknown_node *node;
445         struct jffs2_unknown_node crcnode;
446         uint32_t ofs, prevofs;
447         uint32_t hdr_crc, buf_ofs, buf_len;
448         int err;
449         int noise = 0;
450
451
452 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
453         int cleanmarkerfound = 0;
454 #endif
455
456         ofs = jeb->offset;
457         prevofs = jeb->offset - 1;
458
459         D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs));
460
461 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
462         if (jffs2_cleanmarker_oob(c)) {
463                 int ret = jffs2_check_nand_cleanmarker(c, jeb);
464                 D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret));
465                 /* Even if it's not found, we still scan to see
466                    if the block is empty. We use this information
467                    to decide whether to erase it or not. */
468                 switch (ret) {
469                 case 0:         cleanmarkerfound = 1; break;
470                 case 1:         break;
471                 case 2:         return BLK_STATE_BADBLOCK;
472                 case 3:         return BLK_STATE_ALLDIRTY; /* Block has failed to erase min. once */
473                 default:        return ret;
474                 }
475         }
476 #endif
477
478         if (jffs2_sum_active()) {
479                 struct jffs2_sum_marker *sm;
480                 void *sumptr = NULL;
481                 uint32_t sumlen;
482               
483                 if (!buf_size) {
484                         /* XIP case. Just look, point at the summary if it's there */
485                         sm = (void *)buf + jeb->offset - sizeof(*sm);
486                         if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
487                                 sumptr = buf + je32_to_cpu(sm->offset);
488                                 sumlen = c->sector_size - je32_to_cpu(sm->offset);
489                         }
490                 } else {
491                         /* If NAND flash, read a whole page of it. Else just the end */
492                         if (c->wbuf_pagesize)
493                                 buf_len = c->wbuf_pagesize;
494                         else
495                                 buf_len = sizeof(*sm);
496
497                         /* Read as much as we want into the _end_ of the preallocated buffer */
498                         err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, 
499                                                   jeb->offset + c->sector_size - buf_len,
500                                                   buf_len);                             
501                         if (err)
502                                 return err;
503
504                         sm = (void *)buf + buf_size - sizeof(*sm);
505                         if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
506                                 sumlen = c->sector_size - je32_to_cpu(sm->offset);
507                                 sumptr = buf + buf_size - sumlen;
508
509                                 /* Now, make sure the summary itself is available */
510                                 if (sumlen > buf_size) {
511                                         /* Need to kmalloc for this. */
512                                         sumptr = kmalloc(sumlen, GFP_KERNEL);
513                                         if (!sumptr)
514                                                 return -ENOMEM;
515                                         memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
516                                 }
517                                 if (buf_len < sumlen) {
518                                         /* Need to read more so that the entire summary node is present */
519                                         err = jffs2_fill_scan_buf(c, sumptr, 
520                                                                   jeb->offset + c->sector_size - sumlen,
521                                                                   sumlen - buf_len);                            
522                                         if (err)
523                                                 return err;
524                                 }
525                         }
526
527                 }
528
529                 if (sumptr) {
530                         err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
531                         if (err)
532                                 return err;
533                         if (buf_size && sumlen > buf_size)
534                                 kfree(sumptr);
535                 }
536         }
537
538         buf_ofs = jeb->offset;
539
540         if (!buf_size) {
541                 /* This is the XIP case -- we're reading _directly_ from the flash chip */
542                 buf_len = c->sector_size;
543         } else {
544                 buf_len = EMPTY_SCAN_SIZE(c->sector_size);
545                 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
546                 if (err)
547                         return err;
548         }
549
550         /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
551         ofs = 0;
552
553         /* Scan only 4KiB of 0xFF before declaring it's empty */
554         while(ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
555                 ofs += 4;
556
557         if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) {
558 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
559                 if (jffs2_cleanmarker_oob(c)) {
560                         /* scan oob, take care of cleanmarker */
561                         int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
562                         D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret));
563                         switch (ret) {
564                         case 0:         return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
565                         case 1:         return BLK_STATE_ALLDIRTY;
566                         default:        return ret;
567                         }
568                 }
569 #endif
570                 D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset));
571                 if (c->cleanmarker_size == 0)
572                         return BLK_STATE_CLEANMARKER;   /* don't bother with re-erase */
573                 else
574                         return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
575         }
576         if (ofs) {
577                 D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset,
578                           jeb->offset + ofs));
579                 DIRTY_SPACE(ofs);
580         }
581
582         /* Now ofs is a complete physical flash offset as it always was... */
583         ofs += jeb->offset;
584
585         noise = 10;
586
587         dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
588
589 scan_more:
590         while(ofs < jeb->offset + c->sector_size) {
591
592                 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
593
594                 cond_resched();
595
596                 if (ofs & 3) {
597                         printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs);
598                         ofs = PAD(ofs);
599                         continue;
600                 }
601                 if (ofs == prevofs) {
602                         printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs);
603                         DIRTY_SPACE(4);
604                         ofs += 4;
605                         continue;
606                 }
607                 prevofs = ofs;
608
609                 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
610                         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),
611                                   jeb->offset, c->sector_size, ofs, sizeof(*node)));
612                         DIRTY_SPACE((jeb->offset + c->sector_size)-ofs);
613                         break;
614                 }
615
616                 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
617                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
618                         D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
619                                   sizeof(struct jffs2_unknown_node), buf_len, ofs));
620                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
621                         if (err)
622                                 return err;
623                         buf_ofs = ofs;
624                 }
625
626                 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
627
628                 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
629                         uint32_t inbuf_ofs;
630                         uint32_t empty_start;
631
632                         empty_start = ofs;
633                         ofs += 4;
634
635                         D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs));
636                 more_empty:
637                         inbuf_ofs = ofs - buf_ofs;
638                         while (inbuf_ofs < buf_len) {
639                                 if (*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff) {
640                                         printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n",
641                                                empty_start, ofs);
642                                         DIRTY_SPACE(ofs-empty_start);
643                                         goto scan_more;
644                                 }
645
646                                 inbuf_ofs+=4;
647                                 ofs += 4;
648                         }
649                         /* Ran off end. */
650                         D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs));
651
652                         /* If we're only checking the beginning of a block with a cleanmarker,
653                            bail now */
654                         if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
655                             c->cleanmarker_size && !jeb->dirty_size && !jeb->first_node->next_phys) {
656                                 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size)));
657                                 return BLK_STATE_CLEANMARKER;
658                         }
659
660                         /* See how much more there is to read in this eraseblock... */
661                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
662                         if (!buf_len) {
663                                 /* No more to read. Break out of main loop without marking
664                                    this range of empty space as dirty (because it's not) */
665                                 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n",
666                                           empty_start));
667                                 break;
668                         }
669                         D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs));
670                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
671                         if (err)
672                                 return err;
673                         buf_ofs = ofs;
674                         goto more_empty;
675                 }
676
677                 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
678                         printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs);
679                         DIRTY_SPACE(4);
680                         ofs += 4;
681                         continue;
682                 }
683                 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
684                         D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs));
685                         DIRTY_SPACE(4);
686                         ofs += 4;
687                         continue;
688                 }
689                 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
690                         printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs);
691                         printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n");
692                         DIRTY_SPACE(4);
693                         ofs += 4;
694                         continue;
695                 }
696                 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
697                         /* OK. We're out of possibilities. Whinge and move on */
698                         noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
699                                      JFFS2_MAGIC_BITMASK, ofs,
700                                      je16_to_cpu(node->magic));
701                         DIRTY_SPACE(4);
702                         ofs += 4;
703                         continue;
704                 }
705                 /* We seem to have a node of sorts. Check the CRC */
706                 crcnode.magic = node->magic;
707                 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
708                 crcnode.totlen = node->totlen;
709                 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
710
711                 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
712                         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",
713                                      ofs, je16_to_cpu(node->magic),
714                                      je16_to_cpu(node->nodetype),
715                                      je32_to_cpu(node->totlen),
716                                      je32_to_cpu(node->hdr_crc),
717                                      hdr_crc);
718                         DIRTY_SPACE(4);
719                         ofs += 4;
720                         continue;
721                 }
722
723                 if (ofs + je32_to_cpu(node->totlen) >
724                     jeb->offset + c->sector_size) {
725                         /* Eep. Node goes over the end of the erase block. */
726                         printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
727                                ofs, je32_to_cpu(node->totlen));
728                         printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
729                         DIRTY_SPACE(4);
730                         ofs += 4;
731                         continue;
732                 }
733
734                 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
735                         /* Wheee. This is an obsoleted node */
736                         D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));
737                         DIRTY_SPACE(PAD(je32_to_cpu(node->totlen)));
738                         ofs += PAD(je32_to_cpu(node->totlen));
739                         continue;
740                 }
741
742                 switch(je16_to_cpu(node->nodetype)) {
743                 case JFFS2_NODETYPE_INODE:
744                         if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
745                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
746                                 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
747                                           sizeof(struct jffs2_raw_inode), buf_len, ofs));
748                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
749                                 if (err)
750                                         return err;
751                                 buf_ofs = ofs;
752                                 node = (void *)buf;
753                         }
754                         err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
755                         if (err) return err;
756                         ofs += PAD(je32_to_cpu(node->totlen));
757                         break;
758
759                 case JFFS2_NODETYPE_DIRENT:
760                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
761                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
762                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
763                                           je32_to_cpu(node->totlen), buf_len, ofs));
764                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
765                                 if (err)
766                                         return err;
767                                 buf_ofs = ofs;
768                                 node = (void *)buf;
769                         }
770                         err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
771                         if (err) return err;
772                         ofs += PAD(je32_to_cpu(node->totlen));
773                         break;
774
775 #ifdef CONFIG_JFFS2_FS_XATTR
776                 case JFFS2_NODETYPE_XATTR:
777                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
778                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
779                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)"
780                                           " left to end of buf. Reading 0x%x at 0x%08x\n",
781                                           je32_to_cpu(node->totlen), buf_len, ofs));
782                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
783                                 if (err)
784                                         return err;
785                                 buf_ofs = ofs;
786                                 node = (void *)buf;
787                         }
788                         err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
789                         if (err)
790                                 return err;
791                         ofs += PAD(je32_to_cpu(node->totlen));
792                         break;
793                 case JFFS2_NODETYPE_XREF:
794                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
795                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
796                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)"
797                                           " left to end of buf. Reading 0x%x at 0x%08x\n",
798                                           je32_to_cpu(node->totlen), buf_len, ofs));
799                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
800                                 if (err)
801                                         return err;
802                                 buf_ofs = ofs;
803                                 node = (void *)buf;
804                         }
805                         err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
806                         if (err)
807                                 return err;
808                         ofs += PAD(je32_to_cpu(node->totlen));
809                         break;
810 #endif  /* CONFIG_JFFS2_FS_XATTR */
811
812                 case JFFS2_NODETYPE_CLEANMARKER:
813                         D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs));
814                         if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
815                                 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
816                                        ofs, je32_to_cpu(node->totlen), c->cleanmarker_size);
817                                 DIRTY_SPACE(PAD(sizeof(struct jffs2_unknown_node)));
818                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
819                         } else if (jeb->first_node) {
820                                 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset);
821                                 DIRTY_SPACE(PAD(sizeof(struct jffs2_unknown_node)));
822                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
823                         } else {
824                                 struct jffs2_raw_node_ref *marker_ref = jffs2_alloc_raw_node_ref();
825                                 if (!marker_ref) {
826                                         printk(KERN_NOTICE "Failed to allocate node ref for clean marker\n");
827                                         return -ENOMEM;
828                                 }
829                                 marker_ref->next_in_ino = NULL;
830                                 marker_ref->next_phys = NULL;
831                                 marker_ref->flash_offset = ofs | REF_NORMAL;
832                                 marker_ref->__totlen = c->cleanmarker_size;
833                                 jeb->first_node = jeb->last_node = marker_ref;
834
835                                 USED_SPACE(PAD(c->cleanmarker_size));
836                                 ofs += PAD(c->cleanmarker_size);
837                         }
838                         break;
839
840                 case JFFS2_NODETYPE_PADDING:
841                         if (jffs2_sum_active())
842                                 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
843                         DIRTY_SPACE(PAD(je32_to_cpu(node->totlen)));
844                         ofs += PAD(je32_to_cpu(node->totlen));
845                         break;
846
847                 default:
848                         switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
849                         case JFFS2_FEATURE_ROCOMPAT:
850                                 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
851                                 c->flags |= JFFS2_SB_FLAG_RO;
852                                 if (!(jffs2_is_readonly(c)))
853                                         return -EROFS;
854                                 DIRTY_SPACE(PAD(je32_to_cpu(node->totlen)));
855                                 ofs += PAD(je32_to_cpu(node->totlen));
856                                 break;
857
858                         case JFFS2_FEATURE_INCOMPAT:
859                                 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
860                                 return -EINVAL;
861
862                         case JFFS2_FEATURE_RWCOMPAT_DELETE:
863                                 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
864                                 DIRTY_SPACE(PAD(je32_to_cpu(node->totlen)));
865                                 ofs += PAD(je32_to_cpu(node->totlen));
866                                 break;
867
868                         case JFFS2_FEATURE_RWCOMPAT_COPY:
869                                 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
870                                 USED_SPACE(PAD(je32_to_cpu(node->totlen)));
871                                 ofs += PAD(je32_to_cpu(node->totlen));
872                                 break;
873                         }
874                 }
875         }
876
877         if (jffs2_sum_active()) {
878                 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
879                         dbg_summary("There is not enough space for "
880                                 "summary information, disabling for this jeb!\n");
881                         jffs2_sum_disable_collecting(s);
882                 }
883         }
884
885         D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x\n", jeb->offset,
886                   jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size));
887
888         /* mark_node_obsolete can add to wasted !! */
889         if (jeb->wasted_size) {
890                 jeb->dirty_size += jeb->wasted_size;
891                 c->dirty_size += jeb->wasted_size;
892                 c->wasted_size -= jeb->wasted_size;
893                 jeb->wasted_size = 0;
894         }
895
896         return jffs2_scan_classify_jeb(c, jeb);
897 }
898
899 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
900 {
901         struct jffs2_inode_cache *ic;
902
903         ic = jffs2_get_ino_cache(c, ino);
904         if (ic)
905                 return ic;
906
907         if (ino > c->highest_ino)
908                 c->highest_ino = ino;
909
910         ic = jffs2_alloc_inode_cache();
911         if (!ic) {
912                 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n");
913                 return NULL;
914         }
915         memset(ic, 0, sizeof(*ic));
916
917         ic->ino = ino;
918         ic->nodes = (void *)ic;
919         jffs2_add_ino_cache(c, ic);
920         if (ino == 1)
921                 ic->nlink = 1;
922         return ic;
923 }
924
925 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
926                                  struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
927 {
928         struct jffs2_raw_node_ref *raw;
929         struct jffs2_inode_cache *ic;
930         uint32_t ino = je32_to_cpu(ri->ino);
931
932         D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs));
933
934         /* We do very little here now. Just check the ino# to which we should attribute
935            this node; we can do all the CRC checking etc. later. There's a tradeoff here --
936            we used to scan the flash once only, reading everything we want from it into
937            memory, then building all our in-core data structures and freeing the extra
938            information. Now we allow the first part of the mount to complete a lot quicker,
939            but we have to go _back_ to the flash in order to finish the CRC checking, etc.
940            Which means that the _full_ amount of time to get to proper write mode with GC
941            operational may actually be _longer_ than before. Sucks to be me. */
942
943         raw = jffs2_alloc_raw_node_ref();
944         if (!raw) {
945                 printk(KERN_NOTICE "jffs2_scan_inode_node(): allocation of node reference failed\n");
946                 return -ENOMEM;
947         }
948
949         ic = jffs2_get_ino_cache(c, ino);
950         if (!ic) {
951                 /* Inocache get failed. Either we read a bogus ino# or it's just genuinely the
952                    first node we found for this inode. Do a CRC check to protect against the former
953                    case */
954                 uint32_t crc = crc32(0, ri, sizeof(*ri)-8);
955
956                 if (crc != je32_to_cpu(ri->node_crc)) {
957                         printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
958                                ofs, je32_to_cpu(ri->node_crc), crc);
959                         /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
960                         DIRTY_SPACE(PAD(je32_to_cpu(ri->totlen)));
961                         jffs2_free_raw_node_ref(raw);
962                         return 0;
963                 }
964                 ic = jffs2_scan_make_ino_cache(c, ino);
965                 if (!ic) {
966                         jffs2_free_raw_node_ref(raw);
967                         return -ENOMEM;
968                 }
969         }
970
971         /* Wheee. It worked */
972
973         raw->flash_offset = ofs | REF_UNCHECKED;
974         raw->__totlen = PAD(je32_to_cpu(ri->totlen));
975         raw->next_phys = NULL;
976         raw->next_in_ino = ic->nodes;
977
978         ic->nodes = raw;
979         if (!jeb->first_node)
980                 jeb->first_node = raw;
981         if (jeb->last_node)
982                 jeb->last_node->next_phys = raw;
983         jeb->last_node = raw;
984
985         D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
986                   je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
987                   je32_to_cpu(ri->offset),
988                   je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)));
989
990         pseudo_random += je32_to_cpu(ri->version);
991
992         UNCHECKED_SPACE(PAD(je32_to_cpu(ri->totlen)));
993
994         if (jffs2_sum_active()) {
995                 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
996         }
997
998         return 0;
999 }
1000
1001 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
1002                                   struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
1003 {
1004         struct jffs2_raw_node_ref *raw;
1005         struct jffs2_full_dirent *fd;
1006         struct jffs2_inode_cache *ic;
1007         uint32_t crc;
1008
1009         D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs));
1010
1011         /* We don't get here unless the node is still valid, so we don't have to
1012            mask in the ACCURATE bit any more. */
1013         crc = crc32(0, rd, sizeof(*rd)-8);
1014
1015         if (crc != je32_to_cpu(rd->node_crc)) {
1016                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1017                        ofs, je32_to_cpu(rd->node_crc), crc);
1018                 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1019                 DIRTY_SPACE(PAD(je32_to_cpu(rd->totlen)));
1020                 return 0;
1021         }
1022
1023         pseudo_random += je32_to_cpu(rd->version);
1024
1025         fd = jffs2_alloc_full_dirent(rd->nsize+1);
1026         if (!fd) {
1027                 return -ENOMEM;
1028         }
1029         memcpy(&fd->name, rd->name, rd->nsize);
1030         fd->name[rd->nsize] = 0;
1031
1032         crc = crc32(0, fd->name, rd->nsize);
1033         if (crc != je32_to_cpu(rd->name_crc)) {
1034                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1035                        ofs, je32_to_cpu(rd->name_crc), crc);
1036                 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino)));
1037                 jffs2_free_full_dirent(fd);
1038                 /* FIXME: Why do we believe totlen? */
1039                 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1040                 DIRTY_SPACE(PAD(je32_to_cpu(rd->totlen)));
1041                 return 0;
1042         }
1043         raw = jffs2_alloc_raw_node_ref();
1044         if (!raw) {
1045                 jffs2_free_full_dirent(fd);
1046                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): allocation of node reference failed\n");
1047                 return -ENOMEM;
1048         }
1049         ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1050         if (!ic) {
1051                 jffs2_free_full_dirent(fd);
1052                 jffs2_free_raw_node_ref(raw);
1053                 return -ENOMEM;
1054         }
1055
1056         raw->__totlen = PAD(je32_to_cpu(rd->totlen));
1057         raw->flash_offset = ofs | REF_PRISTINE;
1058         raw->next_phys = NULL;
1059         raw->next_in_ino = ic->nodes;
1060         ic->nodes = raw;
1061         if (!jeb->first_node)
1062                 jeb->first_node = raw;
1063         if (jeb->last_node)
1064                 jeb->last_node->next_phys = raw;
1065         jeb->last_node = raw;
1066
1067         fd->raw = raw;
1068         fd->next = NULL;
1069         fd->version = je32_to_cpu(rd->version);
1070         fd->ino = je32_to_cpu(rd->ino);
1071         fd->nhash = full_name_hash(fd->name, rd->nsize);
1072         fd->type = rd->type;
1073         USED_SPACE(PAD(je32_to_cpu(rd->totlen)));
1074         jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1075
1076         if (jffs2_sum_active()) {
1077                 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1078         }
1079
1080         return 0;
1081 }
1082
1083 static int count_list(struct list_head *l)
1084 {
1085         uint32_t count = 0;
1086         struct list_head *tmp;
1087
1088         list_for_each(tmp, l) {
1089                 count++;
1090         }
1091         return count;
1092 }
1093
1094 /* Note: This breaks if list_empty(head). I don't care. You
1095    might, if you copy this code and use it elsewhere :) */
1096 static void rotate_list(struct list_head *head, uint32_t count)
1097 {
1098         struct list_head *n = head->next;
1099
1100         list_del(head);
1101         while(count--) {
1102                 n = n->next;
1103         }
1104         list_add(head, n);
1105 }
1106
1107 void jffs2_rotate_lists(struct jffs2_sb_info *c)
1108 {
1109         uint32_t x;
1110         uint32_t rotateby;
1111
1112         x = count_list(&c->clean_list);
1113         if (x) {
1114                 rotateby = pseudo_random % x;
1115                 rotate_list((&c->clean_list), rotateby);
1116         }
1117
1118         x = count_list(&c->very_dirty_list);
1119         if (x) {
1120                 rotateby = pseudo_random % x;
1121                 rotate_list((&c->very_dirty_list), rotateby);
1122         }
1123
1124         x = count_list(&c->dirty_list);
1125         if (x) {
1126                 rotateby = pseudo_random % x;
1127                 rotate_list((&c->dirty_list), rotateby);
1128         }
1129
1130         x = count_list(&c->erasable_list);
1131         if (x) {
1132                 rotateby = pseudo_random % x;
1133                 rotate_list((&c->erasable_list), rotateby);
1134         }
1135
1136         if (c->nr_erasing_blocks) {
1137                 rotateby = pseudo_random % c->nr_erasing_blocks;
1138                 rotate_list((&c->erase_pending_list), rotateby);
1139         }
1140
1141         if (c->nr_free_blocks) {
1142                 rotateby = pseudo_random % c->nr_free_blocks;
1143                 rotate_list((&c->free_list), rotateby);
1144         }
1145 }