jffs2: fix another potential leak on error path in scan.c
[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,
101                                     (void **)&flashbuf, NULL);
102                 if (!ret && pointlen < c->mtd->size) {
103                         /* Don't muck about if it won't let us point to the whole flash */
104                         D1(printk(KERN_DEBUG "MTD point returned len too short: 0x%zx\n", pointlen));
105                         c->mtd->unpoint(c->mtd, 0, pointlen);
106                         flashbuf = NULL;
107                 }
108                 if (ret)
109                         D1(printk(KERN_DEBUG "MTD point failed %d\n", ret));
110         }
111 #endif
112         if (!flashbuf) {
113                 /* For NAND it's quicker to read a whole eraseblock at a time,
114                    apparently */
115                 if (jffs2_cleanmarker_oob(c))
116                         buf_size = c->sector_size;
117                 else
118                         buf_size = PAGE_SIZE;
119
120                 /* Respect kmalloc limitations */
121                 if (buf_size > 128*1024)
122                         buf_size = 128*1024;
123
124                 D1(printk(KERN_DEBUG "Allocating readbuf of %d bytes\n", buf_size));
125                 flashbuf = kmalloc(buf_size, GFP_KERNEL);
126                 if (!flashbuf)
127                         return -ENOMEM;
128         }
129
130         if (jffs2_sum_active()) {
131                 s = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL);
132                 if (!s) {
133                         JFFS2_WARNING("Can't allocate memory for summary\n");
134                         ret = -ENOMEM;
135                         goto out;
136                 }
137         }
138
139         for (i=0; i<c->nr_blocks; i++) {
140                 struct jffs2_eraseblock *jeb = &c->blocks[i];
141
142                 cond_resched();
143
144                 /* reset summary info for next eraseblock scan */
145                 jffs2_sum_reset_collected(s);
146
147                 ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
148                                                 buf_size, s);
149
150                 if (ret < 0)
151                         goto out;
152
153                 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
154
155                 /* Now decide which list to put it on */
156                 switch(ret) {
157                 case BLK_STATE_ALLFF:
158                         /*
159                          * Empty block.   Since we can't be sure it
160                          * was entirely erased, we just queue it for erase
161                          * again.  It will be marked as such when the erase
162                          * is complete.  Meanwhile we still count it as empty
163                          * for later checks.
164                          */
165                         empty_blocks++;
166                         list_add(&jeb->list, &c->erase_pending_list);
167                         c->nr_erasing_blocks++;
168                         break;
169
170                 case BLK_STATE_CLEANMARKER:
171                         /* Only a CLEANMARKER node is valid */
172                         if (!jeb->dirty_size) {
173                                 /* It's actually free */
174                                 list_add(&jeb->list, &c->free_list);
175                                 c->nr_free_blocks++;
176                         } else {
177                                 /* Dirt */
178                                 D1(printk(KERN_DEBUG "Adding all-dirty block at 0x%08x to erase_pending_list\n", jeb->offset));
179                                 list_add(&jeb->list, &c->erase_pending_list);
180                                 c->nr_erasing_blocks++;
181                         }
182                         break;
183
184                 case BLK_STATE_CLEAN:
185                         /* Full (or almost full) of clean data. Clean list */
186                         list_add(&jeb->list, &c->clean_list);
187                         break;
188
189                 case BLK_STATE_PARTDIRTY:
190                         /* Some data, but not full. Dirty list. */
191                         /* We want to remember the block with most free space
192                         and stick it in the 'nextblock' position to start writing to it. */
193                         if (jeb->free_size > min_free(c) &&
194                                         (!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
195                                 /* Better candidate for the next writes to go to */
196                                 if (c->nextblock) {
197                                         ret = file_dirty(c, c->nextblock);
198                                         if (ret)
199                                                 goto out;
200                                         /* deleting summary information of the old nextblock */
201                                         jffs2_sum_reset_collected(c->summary);
202                                 }
203                                 /* update collected summary information for the current nextblock */
204                                 jffs2_sum_move_collected(c, s);
205                                 D1(printk(KERN_DEBUG "jffs2_scan_medium(): new nextblock = 0x%08x\n", jeb->offset));
206                                 c->nextblock = jeb;
207                         } else {
208                                 ret = file_dirty(c, jeb);
209                                 if (ret)
210                                         goto out;
211                         }
212                         break;
213
214                 case BLK_STATE_ALLDIRTY:
215                         /* Nothing valid - not even a clean marker. Needs erasing. */
216                         /* For now we just put it on the erasing list. We'll start the erases later */
217                         D1(printk(KERN_NOTICE "JFFS2: Erase block at 0x%08x is not formatted. It will be erased\n", jeb->offset));
218                         list_add(&jeb->list, &c->erase_pending_list);
219                         c->nr_erasing_blocks++;
220                         break;
221
222                 case BLK_STATE_BADBLOCK:
223                         D1(printk(KERN_NOTICE "JFFS2: Block at 0x%08x is bad\n", jeb->offset));
224                         list_add(&jeb->list, &c->bad_list);
225                         c->bad_size += c->sector_size;
226                         c->free_size -= c->sector_size;
227                         bad_blocks++;
228                         break;
229                 default:
230                         printk(KERN_WARNING "jffs2_scan_medium(): unknown block state\n");
231                         BUG();
232                 }
233         }
234
235         /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
236         if (c->nextblock && (c->nextblock->dirty_size)) {
237                 c->nextblock->wasted_size += c->nextblock->dirty_size;
238                 c->wasted_size += c->nextblock->dirty_size;
239                 c->dirty_size -= c->nextblock->dirty_size;
240                 c->nextblock->dirty_size = 0;
241         }
242 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
243         if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) {
244                 /* If we're going to start writing into a block which already
245                    contains data, and the end of the data isn't page-aligned,
246                    skip a little and align it. */
247
248                 uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize;
249
250                 D1(printk(KERN_DEBUG "jffs2_scan_medium(): Skipping %d bytes in nextblock to ensure page alignment\n",
251                           skip));
252                 jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
253                 jffs2_scan_dirty_space(c, c->nextblock, skip);
254         }
255 #endif
256         if (c->nr_erasing_blocks) {
257                 if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) {
258                         printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
259                         printk(KERN_NOTICE "empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",empty_blocks,bad_blocks,c->nr_blocks);
260                         ret = -EIO;
261                         goto out;
262                 }
263                 jffs2_erase_pending_trigger(c);
264         }
265         ret = 0;
266  out:
267         if (buf_size)
268                 kfree(flashbuf);
269 #ifndef __ECOS
270         else
271                 c->mtd->unpoint(c->mtd, 0, c->mtd->size);
272 #endif
273         if (s)
274                 kfree(s);
275
276         return ret;
277 }
278
279 static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf,
280                                uint32_t ofs, uint32_t len)
281 {
282         int ret;
283         size_t retlen;
284
285         ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
286         if (ret) {
287                 D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", len, ofs, ret));
288                 return ret;
289         }
290         if (retlen < len) {
291                 D1(printk(KERN_WARNING "Read at 0x%x gave only 0x%zx bytes\n", ofs, retlen));
292                 return -EIO;
293         }
294         return 0;
295 }
296
297 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
298 {
299         if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
300             && (!jeb->first_node || !ref_next(jeb->first_node)) )
301                 return BLK_STATE_CLEANMARKER;
302
303         /* move blocks with max 4 byte dirty space to cleanlist */
304         else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
305                 c->dirty_size -= jeb->dirty_size;
306                 c->wasted_size += jeb->dirty_size;
307                 jeb->wasted_size += jeb->dirty_size;
308                 jeb->dirty_size = 0;
309                 return BLK_STATE_CLEAN;
310         } else if (jeb->used_size || jeb->unchecked_size)
311                 return BLK_STATE_PARTDIRTY;
312         else
313                 return BLK_STATE_ALLDIRTY;
314 }
315
316 #ifdef CONFIG_JFFS2_FS_XATTR
317 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
318                                  struct jffs2_raw_xattr *rx, uint32_t ofs,
319                                  struct jffs2_summary *s)
320 {
321         struct jffs2_xattr_datum *xd;
322         uint32_t xid, version, totlen, crc;
323         int err;
324
325         crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
326         if (crc != je32_to_cpu(rx->node_crc)) {
327                 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
328                               ofs, je32_to_cpu(rx->node_crc), crc);
329                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
330                         return err;
331                 return 0;
332         }
333
334         xid = je32_to_cpu(rx->xid);
335         version = je32_to_cpu(rx->version);
336
337         totlen = PAD(sizeof(struct jffs2_raw_xattr)
338                         + rx->name_len + 1 + je16_to_cpu(rx->value_len));
339         if (totlen != je32_to_cpu(rx->totlen)) {
340                 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
341                               ofs, je32_to_cpu(rx->totlen), totlen);
342                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
343                         return err;
344                 return 0;
345         }
346
347         xd = jffs2_setup_xattr_datum(c, xid, version);
348         if (IS_ERR(xd))
349                 return PTR_ERR(xd);
350
351         if (xd->version > version) {
352                 struct jffs2_raw_node_ref *raw
353                         = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL);
354                 raw->next_in_ino = xd->node->next_in_ino;
355                 xd->node->next_in_ino = raw;
356         } else {
357                 xd->version = version;
358                 xd->xprefix = rx->xprefix;
359                 xd->name_len = rx->name_len;
360                 xd->value_len = je16_to_cpu(rx->value_len);
361                 xd->data_crc = je32_to_cpu(rx->data_crc);
362
363                 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd);
364         }
365
366         if (jffs2_sum_active())
367                 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
368         dbg_xattr("scaning xdatum at %#08x (xid=%u, version=%u)\n",
369                   ofs, xd->xid, xd->version);
370         return 0;
371 }
372
373 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
374                                 struct jffs2_raw_xref *rr, uint32_t ofs,
375                                 struct jffs2_summary *s)
376 {
377         struct jffs2_xattr_ref *ref;
378         uint32_t crc;
379         int err;
380
381         crc = crc32(0, rr, sizeof(*rr) - 4);
382         if (crc != je32_to_cpu(rr->node_crc)) {
383                 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
384                               ofs, je32_to_cpu(rr->node_crc), crc);
385                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
386                         return err;
387                 return 0;
388         }
389
390         if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
391                 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n",
392                               ofs, je32_to_cpu(rr->totlen),
393                               PAD(sizeof(struct jffs2_raw_xref)));
394                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
395                         return err;
396                 return 0;
397         }
398
399         ref = jffs2_alloc_xattr_ref();
400         if (!ref)
401                 return -ENOMEM;
402
403         /* BEFORE jffs2_build_xattr_subsystem() called, 
404          * and AFTER xattr_ref is marked as a dead xref,
405          * ref->xid is used to store 32bit xid, xd is not used
406          * ref->ino is used to store 32bit inode-number, ic is not used
407          * Thoes variables are declared as union, thus using those
408          * are exclusive. In a similar way, ref->next is temporarily
409          * used to chain all xattr_ref object. It's re-chained to
410          * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
411          */
412         ref->ino = je32_to_cpu(rr->ino);
413         ref->xid = je32_to_cpu(rr->xid);
414         ref->xseqno = je32_to_cpu(rr->xseqno);
415         if (ref->xseqno > c->highest_xseqno)
416                 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
417         ref->next = c->xref_temp;
418         c->xref_temp = ref;
419
420         jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref);
421
422         if (jffs2_sum_active())
423                 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
424         dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
425                   ofs, ref->xid, ref->ino);
426         return 0;
427 }
428 #endif
429
430 /* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
431    the flash, XIP-style */
432 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
433                                   unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
434         struct jffs2_unknown_node *node;
435         struct jffs2_unknown_node crcnode;
436         uint32_t ofs, prevofs;
437         uint32_t hdr_crc, buf_ofs, buf_len;
438         int err;
439         int noise = 0;
440
441
442 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
443         int cleanmarkerfound = 0;
444 #endif
445
446         ofs = jeb->offset;
447         prevofs = jeb->offset - 1;
448
449         D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs));
450
451 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
452         if (jffs2_cleanmarker_oob(c)) {
453                 int ret;
454
455                 if (c->mtd->block_isbad(c->mtd, jeb->offset))
456                         return BLK_STATE_BADBLOCK;
457
458                 ret = jffs2_check_nand_cleanmarker(c, jeb);
459                 D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret));
460
461                 /* Even if it's not found, we still scan to see
462                    if the block is empty. We use this information
463                    to decide whether to erase it or not. */
464                 switch (ret) {
465                 case 0:         cleanmarkerfound = 1; break;
466                 case 1:         break;
467                 default:        return ret;
468                 }
469         }
470 #endif
471
472         if (jffs2_sum_active()) {
473                 struct jffs2_sum_marker *sm;
474                 void *sumptr = NULL;
475                 uint32_t sumlen;
476               
477                 if (!buf_size) {
478                         /* XIP case. Just look, point at the summary if it's there */
479                         sm = (void *)buf + c->sector_size - sizeof(*sm);
480                         if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
481                                 sumptr = buf + je32_to_cpu(sm->offset);
482                                 sumlen = c->sector_size - je32_to_cpu(sm->offset);
483                         }
484                 } else {
485                         /* If NAND flash, read a whole page of it. Else just the end */
486                         if (c->wbuf_pagesize)
487                                 buf_len = c->wbuf_pagesize;
488                         else
489                                 buf_len = sizeof(*sm);
490
491                         /* Read as much as we want into the _end_ of the preallocated buffer */
492                         err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, 
493                                                   jeb->offset + c->sector_size - buf_len,
494                                                   buf_len);                             
495                         if (err)
496                                 return err;
497
498                         sm = (void *)buf + buf_size - sizeof(*sm);
499                         if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
500                                 sumlen = c->sector_size - je32_to_cpu(sm->offset);
501                                 sumptr = buf + buf_size - sumlen;
502
503                                 /* Now, make sure the summary itself is available */
504                                 if (sumlen > buf_size) {
505                                         /* Need to kmalloc for this. */
506                                         sumptr = kmalloc(sumlen, GFP_KERNEL);
507                                         if (!sumptr)
508                                                 return -ENOMEM;
509                                         memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
510                                 }
511                                 if (buf_len < sumlen) {
512                                         /* Need to read more so that the entire summary node is present */
513                                         err = jffs2_fill_scan_buf(c, sumptr, 
514                                                                   jeb->offset + c->sector_size - sumlen,
515                                                                   sumlen - buf_len);                            
516                                         if (err)
517                                                 return err;
518                                 }
519                         }
520
521                 }
522
523                 if (sumptr) {
524                         err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
525
526                         if (buf_size && sumlen > buf_size)
527                                 kfree(sumptr);
528                         /* If it returns with a real error, bail. 
529                            If it returns positive, that's a block classification
530                            (i.e. BLK_STATE_xxx) so return that too.
531                            If it returns zero, fall through to full scan. */
532                         if (err)
533                                 return err;
534                 }
535         }
536
537         buf_ofs = jeb->offset;
538
539         if (!buf_size) {
540                 /* This is the XIP case -- we're reading _directly_ from the flash chip */
541                 buf_len = c->sector_size;
542         } else {
543                 buf_len = EMPTY_SCAN_SIZE(c->sector_size);
544                 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
545                 if (err)
546                         return err;
547         }
548
549         /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
550         ofs = 0;
551
552         /* Scan only 4KiB of 0xFF before declaring it's empty */
553         while(ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
554                 ofs += 4;
555
556         if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) {
557 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
558                 if (jffs2_cleanmarker_oob(c)) {
559                         /* scan oob, take care of cleanmarker */
560                         int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
561                         D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret));
562                         switch (ret) {
563                         case 0:         return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
564                         case 1:         return BLK_STATE_ALLDIRTY;
565                         default:        return ret;
566                         }
567                 }
568 #endif
569                 D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset));
570                 if (c->cleanmarker_size == 0)
571                         return BLK_STATE_CLEANMARKER;   /* don't bother with re-erase */
572                 else
573                         return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
574         }
575         if (ofs) {
576                 D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset,
577                           jeb->offset + ofs));
578                 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
579                         return err;
580                 if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
581                         return err;
582         }
583
584         /* Now ofs is a complete physical flash offset as it always was... */
585         ofs += jeb->offset;
586
587         noise = 10;
588
589         dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
590
591 scan_more:
592         while(ofs < jeb->offset + c->sector_size) {
593
594                 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
595
596                 /* Make sure there are node refs available for use */
597                 err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
598                 if (err)
599                         return err;
600
601                 cond_resched();
602
603                 if (ofs & 3) {
604                         printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs);
605                         ofs = PAD(ofs);
606                         continue;
607                 }
608                 if (ofs == prevofs) {
609                         printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs);
610                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
611                                 return err;
612                         ofs += 4;
613                         continue;
614                 }
615                 prevofs = ofs;
616
617                 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
618                         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),
619                                   jeb->offset, c->sector_size, ofs, sizeof(*node)));
620                         if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
621                                 return err;
622                         break;
623                 }
624
625                 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
626                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
627                         D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
628                                   sizeof(struct jffs2_unknown_node), buf_len, ofs));
629                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
630                         if (err)
631                                 return err;
632                         buf_ofs = ofs;
633                 }
634
635                 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
636
637                 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
638                         uint32_t inbuf_ofs;
639                         uint32_t empty_start, scan_end;
640
641                         empty_start = ofs;
642                         ofs += 4;
643                         scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len);
644
645                         D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs));
646                 more_empty:
647                         inbuf_ofs = ofs - buf_ofs;
648                         while (inbuf_ofs < scan_end) {
649                                 if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) {
650                                         printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n",
651                                                empty_start, ofs);
652                                         if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
653                                                 return err;
654                                         goto scan_more;
655                                 }
656
657                                 inbuf_ofs+=4;
658                                 ofs += 4;
659                         }
660                         /* Ran off end. */
661                         D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs));
662
663                         /* If we're only checking the beginning of a block with a cleanmarker,
664                            bail now */
665                         if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
666                             c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
667                                 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size)));
668                                 return BLK_STATE_CLEANMARKER;
669                         }
670                         if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */
671                                 scan_end = buf_len;
672                                 goto more_empty;
673                         }
674                         
675                         /* See how much more there is to read in this eraseblock... */
676                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
677                         if (!buf_len) {
678                                 /* No more to read. Break out of main loop without marking
679                                    this range of empty space as dirty (because it's not) */
680                                 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n",
681                                           empty_start));
682                                 break;
683                         }
684                         /* point never reaches here */
685                         scan_end = buf_len;
686                         D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs));
687                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
688                         if (err)
689                                 return err;
690                         buf_ofs = ofs;
691                         goto more_empty;
692                 }
693
694                 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
695                         printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs);
696                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
697                                 return err;
698                         ofs += 4;
699                         continue;
700                 }
701                 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
702                         D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs));
703                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
704                                 return err;
705                         ofs += 4;
706                         continue;
707                 }
708                 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
709                         printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs);
710                         printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n");
711                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
712                                 return err;
713                         ofs += 4;
714                         continue;
715                 }
716                 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
717                         /* OK. We're out of possibilities. Whinge and move on */
718                         noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
719                                      JFFS2_MAGIC_BITMASK, ofs,
720                                      je16_to_cpu(node->magic));
721                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
722                                 return err;
723                         ofs += 4;
724                         continue;
725                 }
726                 /* We seem to have a node of sorts. Check the CRC */
727                 crcnode.magic = node->magic;
728                 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
729                 crcnode.totlen = node->totlen;
730                 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
731
732                 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
733                         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",
734                                      ofs, je16_to_cpu(node->magic),
735                                      je16_to_cpu(node->nodetype),
736                                      je32_to_cpu(node->totlen),
737                                      je32_to_cpu(node->hdr_crc),
738                                      hdr_crc);
739                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
740                                 return err;
741                         ofs += 4;
742                         continue;
743                 }
744
745                 if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) {
746                         /* Eep. Node goes over the end of the erase block. */
747                         printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
748                                ofs, je32_to_cpu(node->totlen));
749                         printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
750                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
751                                 return err;
752                         ofs += 4;
753                         continue;
754                 }
755
756                 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
757                         /* Wheee. This is an obsoleted node */
758                         D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));
759                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
760                                 return err;
761                         ofs += PAD(je32_to_cpu(node->totlen));
762                         continue;
763                 }
764
765                 switch(je16_to_cpu(node->nodetype)) {
766                 case JFFS2_NODETYPE_INODE:
767                         if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
768                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
769                                 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
770                                           sizeof(struct jffs2_raw_inode), buf_len, ofs));
771                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
772                                 if (err)
773                                         return err;
774                                 buf_ofs = ofs;
775                                 node = (void *)buf;
776                         }
777                         err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
778                         if (err) return err;
779                         ofs += PAD(je32_to_cpu(node->totlen));
780                         break;
781
782                 case JFFS2_NODETYPE_DIRENT:
783                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
784                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
785                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
786                                           je32_to_cpu(node->totlen), buf_len, ofs));
787                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
788                                 if (err)
789                                         return err;
790                                 buf_ofs = ofs;
791                                 node = (void *)buf;
792                         }
793                         err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
794                         if (err) return err;
795                         ofs += PAD(je32_to_cpu(node->totlen));
796                         break;
797
798 #ifdef CONFIG_JFFS2_FS_XATTR
799                 case JFFS2_NODETYPE_XATTR:
800                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
801                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
802                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)"
803                                           " left to end of buf. Reading 0x%x at 0x%08x\n",
804                                           je32_to_cpu(node->totlen), buf_len, ofs));
805                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
806                                 if (err)
807                                         return err;
808                                 buf_ofs = ofs;
809                                 node = (void *)buf;
810                         }
811                         err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
812                         if (err)
813                                 return err;
814                         ofs += PAD(je32_to_cpu(node->totlen));
815                         break;
816                 case JFFS2_NODETYPE_XREF:
817                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
818                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
819                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)"
820                                           " left to end of buf. Reading 0x%x at 0x%08x\n",
821                                           je32_to_cpu(node->totlen), buf_len, ofs));
822                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
823                                 if (err)
824                                         return err;
825                                 buf_ofs = ofs;
826                                 node = (void *)buf;
827                         }
828                         err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
829                         if (err)
830                                 return err;
831                         ofs += PAD(je32_to_cpu(node->totlen));
832                         break;
833 #endif  /* CONFIG_JFFS2_FS_XATTR */
834
835                 case JFFS2_NODETYPE_CLEANMARKER:
836                         D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs));
837                         if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
838                                 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
839                                        ofs, je32_to_cpu(node->totlen), c->cleanmarker_size);
840                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
841                                         return err;
842                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
843                         } else if (jeb->first_node) {
844                                 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset);
845                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
846                                         return err;
847                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
848                         } else {
849                                 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
850
851                                 ofs += PAD(c->cleanmarker_size);
852                         }
853                         break;
854
855                 case JFFS2_NODETYPE_PADDING:
856                         if (jffs2_sum_active())
857                                 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
858                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
859                                 return err;
860                         ofs += PAD(je32_to_cpu(node->totlen));
861                         break;
862
863                 default:
864                         switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
865                         case JFFS2_FEATURE_ROCOMPAT:
866                                 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
867                                 c->flags |= JFFS2_SB_FLAG_RO;
868                                 if (!(jffs2_is_readonly(c)))
869                                         return -EROFS;
870                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
871                                         return err;
872                                 ofs += PAD(je32_to_cpu(node->totlen));
873                                 break;
874
875                         case JFFS2_FEATURE_INCOMPAT:
876                                 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
877                                 return -EINVAL;
878
879                         case JFFS2_FEATURE_RWCOMPAT_DELETE:
880                                 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
881                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
882                                         return err;
883                                 ofs += PAD(je32_to_cpu(node->totlen));
884                                 break;
885
886                         case JFFS2_FEATURE_RWCOMPAT_COPY: {
887                                 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
888
889                                 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
890
891                                 /* We can't summarise nodes we don't grok */
892                                 jffs2_sum_disable_collecting(s);
893                                 ofs += PAD(je32_to_cpu(node->totlen));
894                                 break;
895                                 }
896                         }
897                 }
898         }
899
900         if (jffs2_sum_active()) {
901                 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
902                         dbg_summary("There is not enough space for "
903                                 "summary information, disabling for this jeb!\n");
904                         jffs2_sum_disable_collecting(s);
905                 }
906         }
907
908         D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
909                   jeb->offset,jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size, jeb->wasted_size));
910         
911         /* mark_node_obsolete can add to wasted !! */
912         if (jeb->wasted_size) {
913                 jeb->dirty_size += jeb->wasted_size;
914                 c->dirty_size += jeb->wasted_size;
915                 c->wasted_size -= jeb->wasted_size;
916                 jeb->wasted_size = 0;
917         }
918
919         return jffs2_scan_classify_jeb(c, jeb);
920 }
921
922 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
923 {
924         struct jffs2_inode_cache *ic;
925
926         ic = jffs2_get_ino_cache(c, ino);
927         if (ic)
928                 return ic;
929
930         if (ino > c->highest_ino)
931                 c->highest_ino = ino;
932
933         ic = jffs2_alloc_inode_cache();
934         if (!ic) {
935                 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n");
936                 return NULL;
937         }
938         memset(ic, 0, sizeof(*ic));
939
940         ic->ino = ino;
941         ic->nodes = (void *)ic;
942         jffs2_add_ino_cache(c, ic);
943         if (ino == 1)
944                 ic->pino_nlink = 1;
945         return ic;
946 }
947
948 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
949                                  struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
950 {
951         struct jffs2_inode_cache *ic;
952         uint32_t crc, ino = je32_to_cpu(ri->ino);
953
954         D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs));
955
956         /* We do very little here now. Just check the ino# to which we should attribute
957            this node; we can do all the CRC checking etc. later. There's a tradeoff here --
958            we used to scan the flash once only, reading everything we want from it into
959            memory, then building all our in-core data structures and freeing the extra
960            information. Now we allow the first part of the mount to complete a lot quicker,
961            but we have to go _back_ to the flash in order to finish the CRC checking, etc.
962            Which means that the _full_ amount of time to get to proper write mode with GC
963            operational may actually be _longer_ than before. Sucks to be me. */
964
965         /* Check the node CRC in any case. */
966         crc = crc32(0, ri, sizeof(*ri)-8);
967         if (crc != je32_to_cpu(ri->node_crc)) {
968                 printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on "
969                        "node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
970                        ofs, je32_to_cpu(ri->node_crc), crc);
971                 /*
972                  * We believe totlen because the CRC on the node
973                  * _header_ was OK, just the node itself failed.
974                  */
975                 return jffs2_scan_dirty_space(c, jeb,
976                                               PAD(je32_to_cpu(ri->totlen)));
977         }
978
979         ic = jffs2_get_ino_cache(c, ino);
980         if (!ic) {
981                 ic = jffs2_scan_make_ino_cache(c, ino);
982                 if (!ic)
983                         return -ENOMEM;
984         }
985
986         /* Wheee. It worked */
987         jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
988
989         D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
990                   je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
991                   je32_to_cpu(ri->offset),
992                   je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)));
993
994         pseudo_random += je32_to_cpu(ri->version);
995
996         if (jffs2_sum_active()) {
997                 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
998         }
999
1000         return 0;
1001 }
1002
1003 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
1004                                   struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
1005 {
1006         struct jffs2_full_dirent *fd;
1007         struct jffs2_inode_cache *ic;
1008         uint32_t checkedlen;
1009         uint32_t crc;
1010         int err;
1011
1012         D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs));
1013
1014         /* We don't get here unless the node is still valid, so we don't have to
1015            mask in the ACCURATE bit any more. */
1016         crc = crc32(0, rd, sizeof(*rd)-8);
1017
1018         if (crc != je32_to_cpu(rd->node_crc)) {
1019                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1020                        ofs, je32_to_cpu(rd->node_crc), crc);
1021                 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1022                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1023                         return err;
1024                 return 0;
1025         }
1026
1027         pseudo_random += je32_to_cpu(rd->version);
1028
1029         /* Should never happen. Did. (OLPC trac #4184)*/
1030         checkedlen = strnlen(rd->name, rd->nsize);
1031         if (checkedlen < rd->nsize) {
1032                 printk(KERN_ERR "Dirent at %08x has zeroes in name. Truncating to %d chars\n",
1033                        ofs, checkedlen);
1034         }
1035         fd = jffs2_alloc_full_dirent(checkedlen+1);
1036         if (!fd) {
1037                 return -ENOMEM;
1038         }
1039         memcpy(&fd->name, rd->name, checkedlen);
1040         fd->name[checkedlen] = 0;
1041
1042         crc = crc32(0, fd->name, rd->nsize);
1043         if (crc != je32_to_cpu(rd->name_crc)) {
1044                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1045                        ofs, je32_to_cpu(rd->name_crc), crc);
1046                 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino)));
1047                 jffs2_free_full_dirent(fd);
1048                 /* FIXME: Why do we believe totlen? */
1049                 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1050                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1051                         return err;
1052                 return 0;
1053         }
1054         ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1055         if (!ic) {
1056                 jffs2_free_full_dirent(fd);
1057                 return -ENOMEM;
1058         }
1059
1060         fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd),
1061                                       PAD(je32_to_cpu(rd->totlen)), ic);
1062
1063         fd->next = NULL;
1064         fd->version = je32_to_cpu(rd->version);
1065         fd->ino = je32_to_cpu(rd->ino);
1066         fd->nhash = full_name_hash(fd->name, checkedlen);
1067         fd->type = rd->type;
1068         jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1069
1070         if (jffs2_sum_active()) {
1071                 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1072         }
1073
1074         return 0;
1075 }
1076
1077 static int count_list(struct list_head *l)
1078 {
1079         uint32_t count = 0;
1080         struct list_head *tmp;
1081
1082         list_for_each(tmp, l) {
1083                 count++;
1084         }
1085         return count;
1086 }
1087
1088 /* Note: This breaks if list_empty(head). I don't care. You
1089    might, if you copy this code and use it elsewhere :) */
1090 static void rotate_list(struct list_head *head, uint32_t count)
1091 {
1092         struct list_head *n = head->next;
1093
1094         list_del(head);
1095         while(count--) {
1096                 n = n->next;
1097         }
1098         list_add(head, n);
1099 }
1100
1101 void jffs2_rotate_lists(struct jffs2_sb_info *c)
1102 {
1103         uint32_t x;
1104         uint32_t rotateby;
1105
1106         x = count_list(&c->clean_list);
1107         if (x) {
1108                 rotateby = pseudo_random % x;
1109                 rotate_list((&c->clean_list), rotateby);
1110         }
1111
1112         x = count_list(&c->very_dirty_list);
1113         if (x) {
1114                 rotateby = pseudo_random % x;
1115                 rotate_list((&c->very_dirty_list), rotateby);
1116         }
1117
1118         x = count_list(&c->dirty_list);
1119         if (x) {
1120                 rotateby = pseudo_random % x;
1121                 rotate_list((&c->dirty_list), rotateby);
1122         }
1123
1124         x = count_list(&c->erasable_list);
1125         if (x) {
1126                 rotateby = pseudo_random % x;
1127                 rotate_list((&c->erasable_list), rotateby);
1128         }
1129
1130         if (c->nr_erasing_blocks) {
1131                 rotateby = pseudo_random % c->nr_erasing_blocks;
1132                 rotate_list((&c->erase_pending_list), rotateby);
1133         }
1134
1135         if (c->nr_free_blocks) {
1136                 rotateby = pseudo_random % c->nr_free_blocks;
1137                 rotate_list((&c->free_list), rotateby);
1138         }
1139 }