]> pilppa.org Git - linux-2.6-omap-h63xx.git/blob - fs/jffs2/scan.c
Merge branch 'master' into upstream-fixes
[linux-2.6-omap-h63xx.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 static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
69 {
70         int ret;
71
72         if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
73                 return ret;
74         if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size)))
75                 return ret;
76         /* Turned wasted size into dirty, since we apparently 
77            think it's recoverable now. */
78         jeb->dirty_size += jeb->wasted_size;
79         c->dirty_size += jeb->wasted_size;
80         c->wasted_size -= jeb->wasted_size;
81         jeb->wasted_size = 0;
82         if (VERYDIRTY(c, jeb->dirty_size)) {
83                 list_add(&jeb->list, &c->very_dirty_list);
84         } else {
85                 list_add(&jeb->list, &c->dirty_list);
86         }
87         return 0;
88 }
89
90 int jffs2_scan_medium(struct jffs2_sb_info *c)
91 {
92         int i, ret;
93         uint32_t empty_blocks = 0, bad_blocks = 0;
94         unsigned char *flashbuf = NULL;
95         uint32_t buf_size = 0;
96         struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
97 #ifndef __ECOS
98         size_t pointlen;
99
100         if (c->mtd->point) {
101                 ret = c->mtd->point (c->mtd, 0, c->mtd->size, &pointlen, &flashbuf);
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, flashbuf, 0, c->mtd->size);
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                         kfree(flashbuf);
134                         JFFS2_WARNING("Can't allocate memory for summary\n");
135                         return -ENOMEM;
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                                                 return ret;
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                                         return ret;
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, flashbuf, 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 = jffs2_check_nand_cleanmarker(c, jeb);
454                 D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret));
455                 /* Even if it's not found, we still scan to see
456                    if the block is empty. We use this information
457                    to decide whether to erase it or not. */
458                 switch (ret) {
459                 case 0:         cleanmarkerfound = 1; break;
460                 case 1:         break;
461                 case 2:         return BLK_STATE_BADBLOCK;
462                 case 3:         return BLK_STATE_ALLDIRTY; /* Block has failed to erase min. once */
463                 default:        return ret;
464                 }
465         }
466 #endif
467
468         if (jffs2_sum_active()) {
469                 struct jffs2_sum_marker *sm;
470                 void *sumptr = NULL;
471                 uint32_t sumlen;
472               
473                 if (!buf_size) {
474                         /* XIP case. Just look, point at the summary if it's there */
475                         sm = (void *)buf + c->sector_size - sizeof(*sm);
476                         if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
477                                 sumptr = buf + je32_to_cpu(sm->offset);
478                                 sumlen = c->sector_size - je32_to_cpu(sm->offset);
479                         }
480                 } else {
481                         /* If NAND flash, read a whole page of it. Else just the end */
482                         if (c->wbuf_pagesize)
483                                 buf_len = c->wbuf_pagesize;
484                         else
485                                 buf_len = sizeof(*sm);
486
487                         /* Read as much as we want into the _end_ of the preallocated buffer */
488                         err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, 
489                                                   jeb->offset + c->sector_size - buf_len,
490                                                   buf_len);                             
491                         if (err)
492                                 return err;
493
494                         sm = (void *)buf + buf_size - sizeof(*sm);
495                         if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
496                                 sumlen = c->sector_size - je32_to_cpu(sm->offset);
497                                 sumptr = buf + buf_size - sumlen;
498
499                                 /* Now, make sure the summary itself is available */
500                                 if (sumlen > buf_size) {
501                                         /* Need to kmalloc for this. */
502                                         sumptr = kmalloc(sumlen, GFP_KERNEL);
503                                         if (!sumptr)
504                                                 return -ENOMEM;
505                                         memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
506                                 }
507                                 if (buf_len < sumlen) {
508                                         /* Need to read more so that the entire summary node is present */
509                                         err = jffs2_fill_scan_buf(c, sumptr, 
510                                                                   jeb->offset + c->sector_size - sumlen,
511                                                                   sumlen - buf_len);                            
512                                         if (err)
513                                                 return err;
514                                 }
515                         }
516
517                 }
518
519                 if (sumptr) {
520                         err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
521
522                         if (buf_size && sumlen > buf_size)
523                                 kfree(sumptr);
524                         /* If it returns with a real error, bail. 
525                            If it returns positive, that's a block classification
526                            (i.e. BLK_STATE_xxx) so return that too.
527                            If it returns zero, fall through to full scan. */
528                         if (err)
529                                 return err;
530                 }
531         }
532
533         buf_ofs = jeb->offset;
534
535         if (!buf_size) {
536                 /* This is the XIP case -- we're reading _directly_ from the flash chip */
537                 buf_len = c->sector_size;
538         } else {
539                 buf_len = EMPTY_SCAN_SIZE(c->sector_size);
540                 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
541                 if (err)
542                         return err;
543         }
544
545         /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
546         ofs = 0;
547
548         /* Scan only 4KiB of 0xFF before declaring it's empty */
549         while(ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
550                 ofs += 4;
551
552         if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) {
553 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
554                 if (jffs2_cleanmarker_oob(c)) {
555                         /* scan oob, take care of cleanmarker */
556                         int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
557                         D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret));
558                         switch (ret) {
559                         case 0:         return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
560                         case 1:         return BLK_STATE_ALLDIRTY;
561                         default:        return ret;
562                         }
563                 }
564 #endif
565                 D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset));
566                 if (c->cleanmarker_size == 0)
567                         return BLK_STATE_CLEANMARKER;   /* don't bother with re-erase */
568                 else
569                         return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
570         }
571         if (ofs) {
572                 D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset,
573                           jeb->offset + ofs));
574                 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
575                         return err;
576                 if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
577                         return err;
578         }
579
580         /* Now ofs is a complete physical flash offset as it always was... */
581         ofs += jeb->offset;
582
583         noise = 10;
584
585         dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
586
587 scan_more:
588         while(ofs < jeb->offset + c->sector_size) {
589
590                 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
591
592                 /* Make sure there are node refs available for use */
593                 err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
594                 if (err)
595                         return err;
596
597                 cond_resched();
598
599                 if (ofs & 3) {
600                         printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs);
601                         ofs = PAD(ofs);
602                         continue;
603                 }
604                 if (ofs == prevofs) {
605                         printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs);
606                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
607                                 return err;
608                         ofs += 4;
609                         continue;
610                 }
611                 prevofs = ofs;
612
613                 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
614                         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),
615                                   jeb->offset, c->sector_size, ofs, sizeof(*node)));
616                         if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
617                                 return err;
618                         break;
619                 }
620
621                 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
622                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
623                         D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
624                                   sizeof(struct jffs2_unknown_node), buf_len, ofs));
625                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
626                         if (err)
627                                 return err;
628                         buf_ofs = ofs;
629                 }
630
631                 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
632
633                 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
634                         uint32_t inbuf_ofs;
635                         uint32_t empty_start;
636
637                         empty_start = ofs;
638                         ofs += 4;
639
640                         D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs));
641                 more_empty:
642                         inbuf_ofs = ofs - buf_ofs;
643                         while (inbuf_ofs < buf_len) {
644                                 if (*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff) {
645                                         printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n",
646                                                empty_start, ofs);
647                                         if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
648                                                 return err;
649                                         goto scan_more;
650                                 }
651
652                                 inbuf_ofs+=4;
653                                 ofs += 4;
654                         }
655                         /* Ran off end. */
656                         D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs));
657
658                         /* If we're only checking the beginning of a block with a cleanmarker,
659                            bail now */
660                         if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
661                             c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
662                                 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size)));
663                                 return BLK_STATE_CLEANMARKER;
664                         }
665
666                         /* See how much more there is to read in this eraseblock... */
667                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
668                         if (!buf_len) {
669                                 /* No more to read. Break out of main loop without marking
670                                    this range of empty space as dirty (because it's not) */
671                                 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n",
672                                           empty_start));
673                                 break;
674                         }
675                         D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs));
676                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
677                         if (err)
678                                 return err;
679                         buf_ofs = ofs;
680                         goto more_empty;
681                 }
682
683                 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
684                         printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs);
685                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
686                                 return err;
687                         ofs += 4;
688                         continue;
689                 }
690                 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
691                         D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs));
692                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
693                                 return err;
694                         ofs += 4;
695                         continue;
696                 }
697                 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
698                         printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs);
699                         printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n");
700                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
701                                 return err;
702                         ofs += 4;
703                         continue;
704                 }
705                 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
706                         /* OK. We're out of possibilities. Whinge and move on */
707                         noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
708                                      JFFS2_MAGIC_BITMASK, ofs,
709                                      je16_to_cpu(node->magic));
710                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
711                                 return err;
712                         ofs += 4;
713                         continue;
714                 }
715                 /* We seem to have a node of sorts. Check the CRC */
716                 crcnode.magic = node->magic;
717                 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
718                 crcnode.totlen = node->totlen;
719                 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
720
721                 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
722                         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",
723                                      ofs, je16_to_cpu(node->magic),
724                                      je16_to_cpu(node->nodetype),
725                                      je32_to_cpu(node->totlen),
726                                      je32_to_cpu(node->hdr_crc),
727                                      hdr_crc);
728                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
729                                 return err;
730                         ofs += 4;
731                         continue;
732                 }
733
734                 if (ofs + je32_to_cpu(node->totlen) >
735                     jeb->offset + c->sector_size) {
736                         /* Eep. Node goes over the end of the erase block. */
737                         printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
738                                ofs, je32_to_cpu(node->totlen));
739                         printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
740                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
741                                 return err;
742                         ofs += 4;
743                         continue;
744                 }
745
746                 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
747                         /* Wheee. This is an obsoleted node */
748                         D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));
749                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
750                                 return err;
751                         ofs += PAD(je32_to_cpu(node->totlen));
752                         continue;
753                 }
754
755                 switch(je16_to_cpu(node->nodetype)) {
756                 case JFFS2_NODETYPE_INODE:
757                         if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
758                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
759                                 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
760                                           sizeof(struct jffs2_raw_inode), buf_len, ofs));
761                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
762                                 if (err)
763                                         return err;
764                                 buf_ofs = ofs;
765                                 node = (void *)buf;
766                         }
767                         err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
768                         if (err) return err;
769                         ofs += PAD(je32_to_cpu(node->totlen));
770                         break;
771
772                 case JFFS2_NODETYPE_DIRENT:
773                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
774                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
775                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
776                                           je32_to_cpu(node->totlen), buf_len, ofs));
777                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
778                                 if (err)
779                                         return err;
780                                 buf_ofs = ofs;
781                                 node = (void *)buf;
782                         }
783                         err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
784                         if (err) return err;
785                         ofs += PAD(je32_to_cpu(node->totlen));
786                         break;
787
788 #ifdef CONFIG_JFFS2_FS_XATTR
789                 case JFFS2_NODETYPE_XATTR:
790                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
791                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
792                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)"
793                                           " left to end of buf. Reading 0x%x at 0x%08x\n",
794                                           je32_to_cpu(node->totlen), buf_len, ofs));
795                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
796                                 if (err)
797                                         return err;
798                                 buf_ofs = ofs;
799                                 node = (void *)buf;
800                         }
801                         err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
802                         if (err)
803                                 return err;
804                         ofs += PAD(je32_to_cpu(node->totlen));
805                         break;
806                 case JFFS2_NODETYPE_XREF:
807                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
808                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
809                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)"
810                                           " left to end of buf. Reading 0x%x at 0x%08x\n",
811                                           je32_to_cpu(node->totlen), buf_len, ofs));
812                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
813                                 if (err)
814                                         return err;
815                                 buf_ofs = ofs;
816                                 node = (void *)buf;
817                         }
818                         err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
819                         if (err)
820                                 return err;
821                         ofs += PAD(je32_to_cpu(node->totlen));
822                         break;
823 #endif  /* CONFIG_JFFS2_FS_XATTR */
824
825                 case JFFS2_NODETYPE_CLEANMARKER:
826                         D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs));
827                         if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
828                                 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
829                                        ofs, je32_to_cpu(node->totlen), c->cleanmarker_size);
830                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
831                                         return err;
832                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
833                         } else if (jeb->first_node) {
834                                 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset);
835                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
836                                         return err;
837                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
838                         } else {
839                                 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
840
841                                 ofs += PAD(c->cleanmarker_size);
842                         }
843                         break;
844
845                 case JFFS2_NODETYPE_PADDING:
846                         if (jffs2_sum_active())
847                                 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
848                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
849                                 return err;
850                         ofs += PAD(je32_to_cpu(node->totlen));
851                         break;
852
853                 default:
854                         switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
855                         case JFFS2_FEATURE_ROCOMPAT:
856                                 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
857                                 c->flags |= JFFS2_SB_FLAG_RO;
858                                 if (!(jffs2_is_readonly(c)))
859                                         return -EROFS;
860                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
861                                         return err;
862                                 ofs += PAD(je32_to_cpu(node->totlen));
863                                 break;
864
865                         case JFFS2_FEATURE_INCOMPAT:
866                                 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
867                                 return -EINVAL;
868
869                         case JFFS2_FEATURE_RWCOMPAT_DELETE:
870                                 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
871                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
872                                         return err;
873                                 ofs += PAD(je32_to_cpu(node->totlen));
874                                 break;
875
876                         case JFFS2_FEATURE_RWCOMPAT_COPY: {
877                                 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
878
879                                 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
880
881                                 /* We can't summarise nodes we don't grok */
882                                 jffs2_sum_disable_collecting(s);
883                                 ofs += PAD(je32_to_cpu(node->totlen));
884                                 break;
885                                 }
886                         }
887                 }
888         }
889
890         if (jffs2_sum_active()) {
891                 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
892                         dbg_summary("There is not enough space for "
893                                 "summary information, disabling for this jeb!\n");
894                         jffs2_sum_disable_collecting(s);
895                 }
896         }
897
898         D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
899                   jeb->offset,jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size, jeb->wasted_size));
900         
901         /* mark_node_obsolete can add to wasted !! */
902         if (jeb->wasted_size) {
903                 jeb->dirty_size += jeb->wasted_size;
904                 c->dirty_size += jeb->wasted_size;
905                 c->wasted_size -= jeb->wasted_size;
906                 jeb->wasted_size = 0;
907         }
908
909         return jffs2_scan_classify_jeb(c, jeb);
910 }
911
912 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
913 {
914         struct jffs2_inode_cache *ic;
915
916         ic = jffs2_get_ino_cache(c, ino);
917         if (ic)
918                 return ic;
919
920         if (ino > c->highest_ino)
921                 c->highest_ino = ino;
922
923         ic = jffs2_alloc_inode_cache();
924         if (!ic) {
925                 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n");
926                 return NULL;
927         }
928         memset(ic, 0, sizeof(*ic));
929
930         ic->ino = ino;
931         ic->nodes = (void *)ic;
932         jffs2_add_ino_cache(c, ic);
933         if (ino == 1)
934                 ic->nlink = 1;
935         return ic;
936 }
937
938 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
939                                  struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
940 {
941         struct jffs2_inode_cache *ic;
942         uint32_t ino = je32_to_cpu(ri->ino);
943         int err;
944
945         D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs));
946
947         /* We do very little here now. Just check the ino# to which we should attribute
948            this node; we can do all the CRC checking etc. later. There's a tradeoff here --
949            we used to scan the flash once only, reading everything we want from it into
950            memory, then building all our in-core data structures and freeing the extra
951            information. Now we allow the first part of the mount to complete a lot quicker,
952            but we have to go _back_ to the flash in order to finish the CRC checking, etc.
953            Which means that the _full_ amount of time to get to proper write mode with GC
954            operational may actually be _longer_ than before. Sucks to be me. */
955
956         ic = jffs2_get_ino_cache(c, ino);
957         if (!ic) {
958                 /* Inocache get failed. Either we read a bogus ino# or it's just genuinely the
959                    first node we found for this inode. Do a CRC check to protect against the former
960                    case */
961                 uint32_t crc = crc32(0, ri, sizeof(*ri)-8);
962
963                 if (crc != je32_to_cpu(ri->node_crc)) {
964                         printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
965                                ofs, je32_to_cpu(ri->node_crc), crc);
966                         /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
967                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(ri->totlen)))))
968                                 return err;
969                         return 0;
970                 }
971                 ic = jffs2_scan_make_ino_cache(c, ino);
972                 if (!ic)
973                         return -ENOMEM;
974         }
975
976         /* Wheee. It worked */
977         jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
978
979         D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
980                   je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
981                   je32_to_cpu(ri->offset),
982                   je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)));
983
984         pseudo_random += je32_to_cpu(ri->version);
985
986         if (jffs2_sum_active()) {
987                 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
988         }
989
990         return 0;
991 }
992
993 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
994                                   struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
995 {
996         struct jffs2_full_dirent *fd;
997         struct jffs2_inode_cache *ic;
998         uint32_t crc;
999         int err;
1000
1001         D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs));
1002
1003         /* We don't get here unless the node is still valid, so we don't have to
1004            mask in the ACCURATE bit any more. */
1005         crc = crc32(0, rd, sizeof(*rd)-8);
1006
1007         if (crc != je32_to_cpu(rd->node_crc)) {
1008                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1009                        ofs, je32_to_cpu(rd->node_crc), crc);
1010                 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1011                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1012                         return err;
1013                 return 0;
1014         }
1015
1016         pseudo_random += je32_to_cpu(rd->version);
1017
1018         fd = jffs2_alloc_full_dirent(rd->nsize+1);
1019         if (!fd) {
1020                 return -ENOMEM;
1021         }
1022         memcpy(&fd->name, rd->name, rd->nsize);
1023         fd->name[rd->nsize] = 0;
1024
1025         crc = crc32(0, fd->name, rd->nsize);
1026         if (crc != je32_to_cpu(rd->name_crc)) {
1027                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1028                        ofs, je32_to_cpu(rd->name_crc), crc);
1029                 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino)));
1030                 jffs2_free_full_dirent(fd);
1031                 /* FIXME: Why do we believe totlen? */
1032                 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1033                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1034                         return err;
1035                 return 0;
1036         }
1037         ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1038         if (!ic) {
1039                 jffs2_free_full_dirent(fd);
1040                 return -ENOMEM;
1041         }
1042
1043         fd->raw = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rd->totlen)), ic);
1044
1045         fd->next = NULL;
1046         fd->version = je32_to_cpu(rd->version);
1047         fd->ino = je32_to_cpu(rd->ino);
1048         fd->nhash = full_name_hash(fd->name, rd->nsize);
1049         fd->type = rd->type;
1050         jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1051
1052         if (jffs2_sum_active()) {
1053                 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1054         }
1055
1056         return 0;
1057 }
1058
1059 static int count_list(struct list_head *l)
1060 {
1061         uint32_t count = 0;
1062         struct list_head *tmp;
1063
1064         list_for_each(tmp, l) {
1065                 count++;
1066         }
1067         return count;
1068 }
1069
1070 /* Note: This breaks if list_empty(head). I don't care. You
1071    might, if you copy this code and use it elsewhere :) */
1072 static void rotate_list(struct list_head *head, uint32_t count)
1073 {
1074         struct list_head *n = head->next;
1075
1076         list_del(head);
1077         while(count--) {
1078                 n = n->next;
1079         }
1080         list_add(head, n);
1081 }
1082
1083 void jffs2_rotate_lists(struct jffs2_sb_info *c)
1084 {
1085         uint32_t x;
1086         uint32_t rotateby;
1087
1088         x = count_list(&c->clean_list);
1089         if (x) {
1090                 rotateby = pseudo_random % x;
1091                 rotate_list((&c->clean_list), rotateby);
1092         }
1093
1094         x = count_list(&c->very_dirty_list);
1095         if (x) {
1096                 rotateby = pseudo_random % x;
1097                 rotate_list((&c->very_dirty_list), rotateby);
1098         }
1099
1100         x = count_list(&c->dirty_list);
1101         if (x) {
1102                 rotateby = pseudo_random % x;
1103                 rotate_list((&c->dirty_list), rotateby);
1104         }
1105
1106         x = count_list(&c->erasable_list);
1107         if (x) {
1108                 rotateby = pseudo_random % x;
1109                 rotate_list((&c->erasable_list), rotateby);
1110         }
1111
1112         if (c->nr_erasing_blocks) {
1113                 rotateby = pseudo_random % c->nr_erasing_blocks;
1114                 rotate_list((&c->erase_pending_list), rotateby);
1115         }
1116
1117         if (c->nr_free_blocks) {
1118                 rotateby = pseudo_random % c->nr_free_blocks;
1119                 rotate_list((&c->free_list), rotateby);
1120         }
1121 }