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Linux 2.6.24-rc8
[pv_ops_mirror.git] / fs / jffs2 / scan.c
blob272872d27fd53242cf50b487c330e112c4b59d06
1 /*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright © 2001-2007 Red Hat, Inc.
5 *
6 * Created by David Woodhouse <dwmw2@infradead.org>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/sched.h>
14 #include <linux/slab.h>
15 #include <linux/mtd/mtd.h>
16 #include <linux/pagemap.h>
17 #include <linux/crc32.h>
18 #include <linux/compiler.h>
19 #include "nodelist.h"
20 #include "summary.h"
21 #include "debug.h"
22
23 #define DEFAULT_EMPTY_SCAN_SIZE 1024
24
25 #define noisy_printk(noise, args...) do { \
26 if (*(noise)) { \
27 printk(KERN_NOTICE args); \
28 (*(noise))--; \
29 if (!(*(noise))) { \
30 printk(KERN_NOTICE "Further such events for this erase block will not be printed\n"); \
31 } \
32 } \
33 } while(0)
34
35 static uint32_t pseudo_random;
36
37 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
38 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s);
39
40 /* These helper functions _must_ increase ofs and also do the dirty/used space accounting.
41 * Returning an error will abort the mount - bad checksums etc. should just mark the space
42 * as dirty.
43 */
44 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
45 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s);
46 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
47 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s);
48
49 static inline int min_free(struct jffs2_sb_info *c)
50 {
51 uint32_t min = 2 * sizeof(struct jffs2_raw_inode);
52 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
53 if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize)
54 return c->wbuf_pagesize;
55 #endif
56 return min;
57
58 }
59
60 static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) {
61 if (sector_size < DEFAULT_EMPTY_SCAN_SIZE)
62 return sector_size;
63 else
64 return DEFAULT_EMPTY_SCAN_SIZE;
65 }
66
67 static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
68 {
69 int ret;
70
71 if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
72 return ret;
73 if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size)))
74 return ret;
75 /* Turned wasted size into dirty, since we apparently
76 think it's recoverable now. */
77 jeb->dirty_size += jeb->wasted_size;
78 c->dirty_size += jeb->wasted_size;
79 c->wasted_size -= jeb->wasted_size;
80 jeb->wasted_size = 0;
81 if (VERYDIRTY(c, jeb->dirty_size)) {
82 list_add(&jeb->list, &c->very_dirty_list);
83 } else {
84 list_add(&jeb->list, &c->dirty_list);
85 }
86 return 0;
87 }
88
89 int jffs2_scan_medium(struct jffs2_sb_info *c)
90 {
91 int i, ret;
92 uint32_t empty_blocks = 0, bad_blocks = 0;
93 unsigned char *flashbuf = NULL;
94 uint32_t buf_size = 0;
95 struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
96 #ifndef __ECOS
97 size_t pointlen;
98
99 if (c->mtd->point) {
100 ret = c->mtd->point (c->mtd, 0, c->mtd->size, &pointlen, &flashbuf);
101 if (!ret && pointlen < c->mtd->size) {
102 /* Don't muck about if it won't let us point to the whole flash */
103 D1(printk(KERN_DEBUG "MTD point returned len too short: 0x%zx\n", pointlen));
104 c->mtd->unpoint(c->mtd, flashbuf, 0, pointlen);
105 flashbuf = NULL;
106 }
107 if (ret)
108 D1(printk(KERN_DEBUG "MTD point failed %d\n", ret));
109 }
110 #endif
111 if (!flashbuf) {
112 /* For NAND it's quicker to read a whole eraseblock at a time,
113 apparently */
114 if (jffs2_cleanmarker_oob(c))
115 buf_size = c->sector_size;
116 else
117 buf_size = PAGE_SIZE;
118
119 /* Respect kmalloc limitations */
120 if (buf_size > 128*1024)
121 buf_size = 128*1024;
122
123 D1(printk(KERN_DEBUG "Allocating readbuf of %d bytes\n", buf_size));
124 flashbuf = kmalloc(buf_size, GFP_KERNEL);
125 if (!flashbuf)
126 return -ENOMEM;
127 }
128
129 if (jffs2_sum_active()) {
130 s = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL);
131 if (!s) {
132 kfree(flashbuf);
133 JFFS2_WARNING("Can't allocate memory for summary\n");
134 return -ENOMEM;
135 }
136 }
137
138 for (i=0; i<c->nr_blocks; i++) {
139 struct jffs2_eraseblock *jeb = &c->blocks[i];
140
141 cond_resched();
142
143 /* reset summary info for next eraseblock scan */
144 jffs2_sum_reset_collected(s);
145
146 ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
147 buf_size, s);
148
149 if (ret < 0)
150 goto out;
151
152 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
153
154 /* Now decide which list to put it on */
155 switch(ret) {
156 case BLK_STATE_ALLFF:
157 /*
158 * Empty block. Since we can't be sure it
159 * was entirely erased, we just queue it for erase
160 * again. It will be marked as such when the erase
161 * is complete. Meanwhile we still count it as empty
162 * for later checks.
163 */
164 empty_blocks++;
165 list_add(&jeb->list, &c->erase_pending_list);
166 c->nr_erasing_blocks++;
167 break;
168
169 case BLK_STATE_CLEANMARKER:
170 /* Only a CLEANMARKER node is valid */
171 if (!jeb->dirty_size) {
172 /* It's actually free */
173 list_add(&jeb->list, &c->free_list);
174 c->nr_free_blocks++;
175 } else {
176 /* Dirt */
177 D1(printk(KERN_DEBUG "Adding all-dirty block at 0x%08x to erase_pending_list\n", jeb->offset));
178 list_add(&jeb->list, &c->erase_pending_list);
179 c->nr_erasing_blocks++;
180 }
181 break;
182
183 case BLK_STATE_CLEAN:
184 /* Full (or almost full) of clean data. Clean list */
185 list_add(&jeb->list, &c->clean_list);
186 break;
187
188 case BLK_STATE_PARTDIRTY:
189 /* Some data, but not full. Dirty list. */
190 /* We want to remember the block with most free space
191 and stick it in the 'nextblock' position to start writing to it. */
192 if (jeb->free_size > min_free(c) &&
193 (!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
194 /* Better candidate for the next writes to go to */
195 if (c->nextblock) {
196 ret = file_dirty(c, c->nextblock);
197 if (ret)
198 return ret;
199 /* deleting summary information of the old nextblock */
200 jffs2_sum_reset_collected(c->summary);
201 }
202 /* update collected summary information for the current nextblock */
203 jffs2_sum_move_collected(c, s);
204 D1(printk(KERN_DEBUG "jffs2_scan_medium(): new nextblock = 0x%08x\n", jeb->offset));
205 c->nextblock = jeb;
206 } else {
207 ret = file_dirty(c, jeb);
208 if (ret)
209 return ret;
210 }
211 break;
212
213 case BLK_STATE_ALLDIRTY:
214 /* Nothing valid - not even a clean marker. Needs erasing. */
215 /* For now we just put it on the erasing list. We'll start the erases later */
216 D1(printk(KERN_NOTICE "JFFS2: Erase block at 0x%08x is not formatted. It will be erased\n", jeb->offset));
217 list_add(&jeb->list, &c->erase_pending_list);
218 c->nr_erasing_blocks++;
219 break;
220
221 case BLK_STATE_BADBLOCK:
222 D1(printk(KERN_NOTICE "JFFS2: Block at 0x%08x is bad\n", jeb->offset));
223 list_add(&jeb->list, &c->bad_list);
224 c->bad_size += c->sector_size;
225 c->free_size -= c->sector_size;
226 bad_blocks++;
227 break;
228 default:
229 printk(KERN_WARNING "jffs2_scan_medium(): unknown block state\n");
230 BUG();
231 }
232 }
233
234 /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
235 if (c->nextblock && (c->nextblock->dirty_size)) {
236 c->nextblock->wasted_size += c->nextblock->dirty_size;
237 c->wasted_size += c->nextblock->dirty_size;
238 c->dirty_size -= c->nextblock->dirty_size;
239 c->nextblock->dirty_size = 0;
240 }
241 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
242 if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) {
243 /* If we're going to start writing into a block which already
244 contains data, and the end of the data isn't page-aligned,
245 skip a little and align it. */
246
247 uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize;
248
249 D1(printk(KERN_DEBUG "jffs2_scan_medium(): Skipping %d bytes in nextblock to ensure page alignment\n",
250 skip));
251 jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
252 jffs2_scan_dirty_space(c, c->nextblock, skip);
253 }
254 #endif
255 if (c->nr_erasing_blocks) {
256 if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) {
257 printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
258 printk(KERN_NOTICE "empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",empty_blocks,bad_blocks,c->nr_blocks);
259 ret = -EIO;
260 goto out;
261 }
262 jffs2_erase_pending_trigger(c);
263 }
264 ret = 0;
265 out:
266 if (buf_size)
267 kfree(flashbuf);
268 #ifndef __ECOS
269 else
270 c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size);
271 #endif
272 if (s)
273 kfree(s);
274
275 return ret;
276 }
277
278 static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf,
279 uint32_t ofs, uint32_t len)
280 {
281 int ret;
282 size_t retlen;
283
284 ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
285 if (ret) {
286 D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", len, ofs, ret));
287 return ret;
288 }
289 if (retlen < len) {
290 D1(printk(KERN_WARNING "Read at 0x%x gave only 0x%zx bytes\n", ofs, retlen));
291 return -EIO;
292 }
293 return 0;
294 }
295
296 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
297 {
298 if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
299 && (!jeb->first_node || !ref_next(jeb->first_node)) )
300 return BLK_STATE_CLEANMARKER;
301
302 /* move blocks with max 4 byte dirty space to cleanlist */
303 else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
304 c->dirty_size -= jeb->dirty_size;
305 c->wasted_size += jeb->dirty_size;
306 jeb->wasted_size += jeb->dirty_size;
307 jeb->dirty_size = 0;
308 return BLK_STATE_CLEAN;
309 } else if (jeb->used_size || jeb->unchecked_size)
310 return BLK_STATE_PARTDIRTY;
311 else
312 return BLK_STATE_ALLDIRTY;
313 }
314
315 #ifdef CONFIG_JFFS2_FS_XATTR
316 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
317 struct jffs2_raw_xattr *rx, uint32_t ofs,
318 struct jffs2_summary *s)
319 {
320 struct jffs2_xattr_datum *xd;
321 uint32_t xid, version, totlen, crc;
322 int err;
323
324 crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
325 if (crc != je32_to_cpu(rx->node_crc)) {
326 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
327 ofs, je32_to_cpu(rx->node_crc), crc);
328 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
329 return err;
330 return 0;
331 }
332
333 xid = je32_to_cpu(rx->xid);
334 version = je32_to_cpu(rx->version);
335
336 totlen = PAD(sizeof(struct jffs2_raw_xattr)
337 + rx->name_len + 1 + je16_to_cpu(rx->value_len));
338 if (totlen != je32_to_cpu(rx->totlen)) {
339 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
340 ofs, je32_to_cpu(rx->totlen), totlen);
341 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
342 return err;
343 return 0;
344 }
345
346 xd = jffs2_setup_xattr_datum(c, xid, version);
347 if (IS_ERR(xd))
348 return PTR_ERR(xd);
349
350 if (xd->version > version) {
351 struct jffs2_raw_node_ref *raw
352 = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL);
353 raw->next_in_ino = xd->node->next_in_ino;
354 xd->node->next_in_ino = raw;
355 } else {
356 xd->version = version;
357 xd->xprefix = rx->xprefix;
358 xd->name_len = rx->name_len;
359 xd->value_len = je16_to_cpu(rx->value_len);
360 xd->data_crc = je32_to_cpu(rx->data_crc);
361
362 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd);
363 }
364
365 if (jffs2_sum_active())
366 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
367 dbg_xattr("scaning xdatum at %#08x (xid=%u, version=%u)\n",
368 ofs, xd->xid, xd->version);
369 return 0;
370 }
371
372 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
373 struct jffs2_raw_xref *rr, uint32_t ofs,
374 struct jffs2_summary *s)
375 {
376 struct jffs2_xattr_ref *ref;
377 uint32_t crc;
378 int err;
379
380 crc = crc32(0, rr, sizeof(*rr) - 4);
381 if (crc != je32_to_cpu(rr->node_crc)) {
382 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
383 ofs, je32_to_cpu(rr->node_crc), crc);
384 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
385 return err;
386 return 0;
387 }
388
389 if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
390 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n",
391 ofs, je32_to_cpu(rr->totlen),
392 PAD(sizeof(struct jffs2_raw_xref)));
393 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
394 return err;
395 return 0;
396 }
397
398 ref = jffs2_alloc_xattr_ref();
399 if (!ref)
400 return -ENOMEM;
401
402 /* BEFORE jffs2_build_xattr_subsystem() called,
403 * and AFTER xattr_ref is marked as a dead xref,
404 * ref->xid is used to store 32bit xid, xd is not used
405 * ref->ino is used to store 32bit inode-number, ic is not used
406 * Thoes variables are declared as union, thus using those
407 * are exclusive. In a similar way, ref->next is temporarily
408 * used to chain all xattr_ref object. It's re-chained to
409 * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
410 */
411 ref->ino = je32_to_cpu(rr->ino);
412 ref->xid = je32_to_cpu(rr->xid);
413 ref->xseqno = je32_to_cpu(rr->xseqno);
414 if (ref->xseqno > c->highest_xseqno)
415 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
416 ref->next = c->xref_temp;
417 c->xref_temp = ref;
418
419 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref);
420
421 if (jffs2_sum_active())
422 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
423 dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
424 ofs, ref->xid, ref->ino);
425 return 0;
426 }
427 #endif
428
429 /* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
430 the flash, XIP-style */
431 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
432 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
433 struct jffs2_unknown_node *node;
434 struct jffs2_unknown_node crcnode;
435 uint32_t ofs, prevofs;
436 uint32_t hdr_crc, buf_ofs, buf_len;
437 int err;
438 int noise = 0;
439
440
441 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
442 int cleanmarkerfound = 0;
443 #endif
444
445 ofs = jeb->offset;
446 prevofs = jeb->offset - 1;
447
448 D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs));
449
450 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
451 if (jffs2_cleanmarker_oob(c)) {
452 int ret;
453
454 if (c->mtd->block_isbad(c->mtd, jeb->offset))
455 return BLK_STATE_BADBLOCK;
456
457 ret = jffs2_check_nand_cleanmarker(c, jeb);
458 D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret));
459
460 /* Even if it's not found, we still scan to see
461 if the block is empty. We use this information
462 to decide whether to erase it or not. */
463 switch (ret) {
464 case 0: cleanmarkerfound = 1; break;
465 case 1: break;
466 default: return ret;
467 }
468 }
469 #endif
470
471 if (jffs2_sum_active()) {
472 struct jffs2_sum_marker *sm;
473 void *sumptr = NULL;
474 uint32_t sumlen;
475
476 if (!buf_size) {
477 /* XIP case. Just look, point at the summary if it's there */
478 sm = (void *)buf + c->sector_size - sizeof(*sm);
479 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
480 sumptr = buf + je32_to_cpu(sm->offset);
481 sumlen = c->sector_size - je32_to_cpu(sm->offset);
482 }
483 } else {
484 /* If NAND flash, read a whole page of it. Else just the end */
485 if (c->wbuf_pagesize)
486 buf_len = c->wbuf_pagesize;
487 else
488 buf_len = sizeof(*sm);
489
490 /* Read as much as we want into the _end_ of the preallocated buffer */
491 err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len,
492 jeb->offset + c->sector_size - buf_len,
493 buf_len);
494 if (err)
495 return err;
496
497 sm = (void *)buf + buf_size - sizeof(*sm);
498 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
499 sumlen = c->sector_size - je32_to_cpu(sm->offset);
500 sumptr = buf + buf_size - sumlen;
501
502 /* Now, make sure the summary itself is available */
503 if (sumlen > buf_size) {
504 /* Need to kmalloc for this. */
505 sumptr = kmalloc(sumlen, GFP_KERNEL);
506 if (!sumptr)
507 return -ENOMEM;
508 memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
509 }
510 if (buf_len < sumlen) {
511 /* Need to read more so that the entire summary node is present */
512 err = jffs2_fill_scan_buf(c, sumptr,
513 jeb->offset + c->sector_size - sumlen,
514 sumlen - buf_len);
515 if (err)
516 return err;
517 }
518 }
519
520 }
521
522 if (sumptr) {
523 err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
524
525 if (buf_size && sumlen > buf_size)
526 kfree(sumptr);
527 /* If it returns with a real error, bail.
528 If it returns positive, that's a block classification
529 (i.e. BLK_STATE_xxx) so return that too.
530 If it returns zero, fall through to full scan. */
531 if (err)
532 return err;
533 }
534 }
535
536 buf_ofs = jeb->offset;
537
538 if (!buf_size) {
539 /* This is the XIP case -- we're reading _directly_ from the flash chip */
540 buf_len = c->sector_size;
541 } else {
542 buf_len = EMPTY_SCAN_SIZE(c->sector_size);
543 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
544 if (err)
545 return err;
546 }
547
548 /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
549 ofs = 0;
550
551 /* Scan only 4KiB of 0xFF before declaring it's empty */
552 while(ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
553 ofs += 4;
554
555 if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) {
556 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
557 if (jffs2_cleanmarker_oob(c)) {
558 /* scan oob, take care of cleanmarker */
559 int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
560 D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret));
561 switch (ret) {
562 case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
563 case 1: return BLK_STATE_ALLDIRTY;
564 default: return ret;
565 }
566 }
567 #endif
568 D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset));
569 if (c->cleanmarker_size == 0)
570 return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */
571 else
572 return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
573 }
574 if (ofs) {
575 D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset,
576 jeb->offset + ofs));
577 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
578 return err;
579 if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
580 return err;
581 }
582
583 /* Now ofs is a complete physical flash offset as it always was... */
584 ofs += jeb->offset;
585
586 noise = 10;
587
588 dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
589
590 scan_more:
591 while(ofs < jeb->offset + c->sector_size) {
592
593 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
594
595 /* Make sure there are node refs available for use */
596 err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
597 if (err)
598 return err;
599
600 cond_resched();
601
602 if (ofs & 3) {
603 printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs);
604 ofs = PAD(ofs);
605 continue;
606 }
607 if (ofs == prevofs) {
608 printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs);
609 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
610 return err;
611 ofs += 4;
612 continue;
613 }
614 prevofs = ofs;
615
616 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
617 D1(printk(KERN_DEBUG "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n", sizeof(struct jffs2_unknown_node),
618 jeb->offset, c->sector_size, ofs, sizeof(*node)));
619 if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
620 return err;
621 break;
622 }
623
624 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
625 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
626 D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
627 sizeof(struct jffs2_unknown_node), buf_len, ofs));
628 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
629 if (err)
630 return err;
631 buf_ofs = ofs;
632 }
633
634 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
635
636 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
637 uint32_t inbuf_ofs;
638 uint32_t empty_start, scan_end;
639
640 empty_start = ofs;
641 ofs += 4;
642 scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len);
643
644 D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs));
645 more_empty:
646 inbuf_ofs = ofs - buf_ofs;
647 while (inbuf_ofs < scan_end) {
648 if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) {
649 printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n",
650 empty_start, ofs);
651 if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
652 return err;
653 goto scan_more;
654 }
655
656 inbuf_ofs+=4;
657 ofs += 4;
658 }
659 /* Ran off end. */
660 D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs));
661
662 /* If we're only checking the beginning of a block with a cleanmarker,
663 bail now */
664 if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
665 c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
666 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size)));
667 return BLK_STATE_CLEANMARKER;
668 }
669 if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */
670 scan_end = buf_len;
671 goto more_empty;
672 }
673
674 /* See how much more there is to read in this eraseblock... */
675 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
676 if (!buf_len) {
677 /* No more to read. Break out of main loop without marking
678 this range of empty space as dirty (because it's not) */
679 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n",
680 empty_start));
681 break;
682 }
683 /* point never reaches here */
684 scan_end = buf_len;
685 D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs));
686 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
687 if (err)
688 return err;
689 buf_ofs = ofs;
690 goto more_empty;
691 }
692
693 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
694 printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs);
695 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
696 return err;
697 ofs += 4;
698 continue;
699 }
700 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
701 D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs));
702 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
703 return err;
704 ofs += 4;
705 continue;
706 }
707 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
708 printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs);
709 printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n");
710 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
711 return err;
712 ofs += 4;
713 continue;
714 }
715 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
716 /* OK. We're out of possibilities. Whinge and move on */
717 noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
718 JFFS2_MAGIC_BITMASK, ofs,
719 je16_to_cpu(node->magic));
720 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
721 return err;
722 ofs += 4;
723 continue;
724 }
725 /* We seem to have a node of sorts. Check the CRC */
726 crcnode.magic = node->magic;
727 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
728 crcnode.totlen = node->totlen;
729 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
730
731 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
732 noisy_printk(&noise, "jffs2_scan_eraseblock(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n",
733 ofs, je16_to_cpu(node->magic),
734 je16_to_cpu(node->nodetype),
735 je32_to_cpu(node->totlen),
736 je32_to_cpu(node->hdr_crc),
737 hdr_crc);
738 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
739 return err;
740 ofs += 4;
741 continue;
742 }
743
744 if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) {
745 /* Eep. Node goes over the end of the erase block. */
746 printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
747 ofs, je32_to_cpu(node->totlen));
748 printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
749 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
750 return err;
751 ofs += 4;
752 continue;
753 }
754
755 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
756 /* Wheee. This is an obsoleted node */
757 D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));
758 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
759 return err;
760 ofs += PAD(je32_to_cpu(node->totlen));
761 continue;
762 }
763
764 switch(je16_to_cpu(node->nodetype)) {
765 case JFFS2_NODETYPE_INODE:
766 if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
767 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
768 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
769 sizeof(struct jffs2_raw_inode), buf_len, ofs));
770 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
771 if (err)
772 return err;
773 buf_ofs = ofs;
774 node = (void *)buf;
775 }
776 err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
777 if (err) return err;
778 ofs += PAD(je32_to_cpu(node->totlen));
779 break;
780
781 case JFFS2_NODETYPE_DIRENT:
782 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
783 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
784 D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
785 je32_to_cpu(node->totlen), buf_len, ofs));
786 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
787 if (err)
788 return err;
789 buf_ofs = ofs;
790 node = (void *)buf;
791 }
792 err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
793 if (err) return err;
794 ofs += PAD(je32_to_cpu(node->totlen));
795 break;
796
797 #ifdef CONFIG_JFFS2_FS_XATTR
798 case JFFS2_NODETYPE_XATTR:
799 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
800 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
801 D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)"
802 " left to end of buf. Reading 0x%x at 0x%08x\n",
803 je32_to_cpu(node->totlen), buf_len, ofs));
804 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
805 if (err)
806 return err;
807 buf_ofs = ofs;
808 node = (void *)buf;
809 }
810 err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
811 if (err)
812 return err;
813 ofs += PAD(je32_to_cpu(node->totlen));
814 break;
815 case JFFS2_NODETYPE_XREF:
816 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
817 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
818 D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)"
819 " left to end of buf. Reading 0x%x at 0x%08x\n",
820 je32_to_cpu(node->totlen), buf_len, ofs));
821 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
822 if (err)
823 return err;
824 buf_ofs = ofs;
825 node = (void *)buf;
826 }
827 err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
828 if (err)
829 return err;
830 ofs += PAD(je32_to_cpu(node->totlen));
831 break;
832 #endif /* CONFIG_JFFS2_FS_XATTR */
833
834 case JFFS2_NODETYPE_CLEANMARKER:
835 D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs));
836 if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
837 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
838 ofs, je32_to_cpu(node->totlen), c->cleanmarker_size);
839 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
840 return err;
841 ofs += PAD(sizeof(struct jffs2_unknown_node));
842 } else if (jeb->first_node) {
843 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset);
844 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
845 return err;
846 ofs += PAD(sizeof(struct jffs2_unknown_node));
847 } else {
848 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
849
850 ofs += PAD(c->cleanmarker_size);
851 }
852 break;
853
854 case JFFS2_NODETYPE_PADDING:
855 if (jffs2_sum_active())
856 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
857 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
858 return err;
859 ofs += PAD(je32_to_cpu(node->totlen));
860 break;
861
862 default:
863 switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
864 case JFFS2_FEATURE_ROCOMPAT:
865 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
866 c->flags |= JFFS2_SB_FLAG_RO;
867 if (!(jffs2_is_readonly(c)))
868 return -EROFS;
869 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
870 return err;
871 ofs += PAD(je32_to_cpu(node->totlen));
872 break;
873
874 case JFFS2_FEATURE_INCOMPAT:
875 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
876 return -EINVAL;
877
878 case JFFS2_FEATURE_RWCOMPAT_DELETE:
879 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
880 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
881 return err;
882 ofs += PAD(je32_to_cpu(node->totlen));
883 break;
884
885 case JFFS2_FEATURE_RWCOMPAT_COPY: {
886 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
887
888 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
889
890 /* We can't summarise nodes we don't grok */
891 jffs2_sum_disable_collecting(s);
892 ofs += PAD(je32_to_cpu(node->totlen));
893 break;
894 }
895 }
896 }
897 }
898
899 if (jffs2_sum_active()) {
900 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
901 dbg_summary("There is not enough space for "
902 "summary information, disabling for this jeb!\n");
903 jffs2_sum_disable_collecting(s);
904 }
905 }
906
907 D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
908 jeb->offset,jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size, jeb->wasted_size));
909
910 /* mark_node_obsolete can add to wasted !! */
911 if (jeb->wasted_size) {
912 jeb->dirty_size += jeb->wasted_size;
913 c->dirty_size += jeb->wasted_size;
914 c->wasted_size -= jeb->wasted_size;
915 jeb->wasted_size = 0;
916 }
917
918 return jffs2_scan_classify_jeb(c, jeb);
919 }
920
921 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
922 {
923 struct jffs2_inode_cache *ic;
924
925 ic = jffs2_get_ino_cache(c, ino);
926 if (ic)
927 return ic;
928
929 if (ino > c->highest_ino)
930 c->highest_ino = ino;
931
932 ic = jffs2_alloc_inode_cache();
933 if (!ic) {
934 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n");
935 return NULL;
936 }
937 memset(ic, 0, sizeof(*ic));
938
939 ic->ino = ino;
940 ic->nodes = (void *)ic;
941 jffs2_add_ino_cache(c, ic);
942 if (ino == 1)
943 ic->nlink = 1;
944 return ic;
945 }
946
947 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
948 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
949 {
950 struct jffs2_inode_cache *ic;
951 uint32_t crc, ino = je32_to_cpu(ri->ino);
952
953 D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs));
954
955 /* We do very little here now. Just check the ino# to which we should attribute
956 this node; we can do all the CRC checking etc. later. There's a tradeoff here --
957 we used to scan the flash once only, reading everything we want from it into
958 memory, then building all our in-core data structures and freeing the extra
959 information. Now we allow the first part of the mount to complete a lot quicker,
960 but we have to go _back_ to the flash in order to finish the CRC checking, etc.
961 Which means that the _full_ amount of time to get to proper write mode with GC
962 operational may actually be _longer_ than before. Sucks to be me. */
963
964 /* Check the node CRC in any case. */
965 crc = crc32(0, ri, sizeof(*ri)-8);
966 if (crc != je32_to_cpu(ri->node_crc)) {
967 printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on "
968 "node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
969 ofs, je32_to_cpu(ri->node_crc), crc);
970 /*
971 * We believe totlen because the CRC on the node
972 * _header_ was OK, just the node itself failed.
973 */
974 return jffs2_scan_dirty_space(c, jeb,
975 PAD(je32_to_cpu(ri->totlen)));
976 }
977
978 ic = jffs2_get_ino_cache(c, ino);
979 if (!ic) {
980 ic = jffs2_scan_make_ino_cache(c, ino);
981 if (!ic)
982 return -ENOMEM;
983 }
984
985 /* Wheee. It worked */
986 jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
987
988 D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
989 je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
990 je32_to_cpu(ri->offset),
991 je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)));
992
993 pseudo_random += je32_to_cpu(ri->version);
994
995 if (jffs2_sum_active()) {
996 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
997 }
998
999 return 0;
1000 }
1001
1002 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
1003 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
1004 {
1005 struct jffs2_full_dirent *fd;
1006 struct jffs2_inode_cache *ic;
1007 uint32_t checkedlen;
1008 uint32_t crc;
1009 int err;
1010
1011 D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs));
1012
1013 /* We don't get here unless the node is still valid, so we don't have to
1014 mask in the ACCURATE bit any more. */
1015 crc = crc32(0, rd, sizeof(*rd)-8);
1016
1017 if (crc != je32_to_cpu(rd->node_crc)) {
1018 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1019 ofs, je32_to_cpu(rd->node_crc), crc);
1020 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1021 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1022 return err;
1023 return 0;
1024 }
1025
1026 pseudo_random += je32_to_cpu(rd->version);
1027
1028 /* Should never happen. Did. (OLPC trac #4184)*/
1029 checkedlen = strnlen(rd->name, rd->nsize);
1030 if (checkedlen < rd->nsize) {
1031 printk(KERN_ERR "Dirent at %08x has zeroes in name. Truncating to %d chars\n",
1032 ofs, checkedlen);
1033 }
1034 fd = jffs2_alloc_full_dirent(checkedlen+1);
1035 if (!fd) {
1036 return -ENOMEM;
1037 }
1038 memcpy(&fd->name, rd->name, checkedlen);
1039 fd->name[checkedlen] = 0;
1040
1041 crc = crc32(0, fd->name, rd->nsize);
1042 if (crc != je32_to_cpu(rd->name_crc)) {
1043 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1044 ofs, je32_to_cpu(rd->name_crc), crc);
1045 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino)));
1046 jffs2_free_full_dirent(fd);
1047 /* FIXME: Why do we believe totlen? */
1048 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1049 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1050 return err;
1051 return 0;
1052 }
1053 ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1054 if (!ic) {
1055 jffs2_free_full_dirent(fd);
1056 return -ENOMEM;
1057 }
1058
1059 fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd),
1060 PAD(je32_to_cpu(rd->totlen)), ic);
1061
1062 fd->next = NULL;
1063 fd->version = je32_to_cpu(rd->version);
1064 fd->ino = je32_to_cpu(rd->ino);
1065 fd->nhash = full_name_hash(fd->name, checkedlen);
1066 fd->type = rd->type;
1067 jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1068
1069 if (jffs2_sum_active()) {
1070 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1071 }
1072
1073 return 0;
1074 }
1075
1076 static int count_list(struct list_head *l)
1077 {
1078 uint32_t count = 0;
1079 struct list_head *tmp;
1080
1081 list_for_each(tmp, l) {
1082 count++;
1083 }
1084 return count;
1085 }
1086
1087 /* Note: This breaks if list_empty(head). I don't care. You
1088 might, if you copy this code and use it elsewhere :) */
1089 static void rotate_list(struct list_head *head, uint32_t count)
1090 {
1091 struct list_head *n = head->next;
1092
1093 list_del(head);
1094 while(count--) {
1095 n = n->next;
1096 }
1097 list_add(head, n);
1098 }
1099
1100 void jffs2_rotate_lists(struct jffs2_sb_info *c)
1101 {
1102 uint32_t x;
1103 uint32_t rotateby;
1104
1105 x = count_list(&c->clean_list);
1106 if (x) {
1107 rotateby = pseudo_random % x;
1108 rotate_list((&c->clean_list), rotateby);
1109 }
1110
1111 x = count_list(&c->very_dirty_list);
1112 if (x) {
1113 rotateby = pseudo_random % x;
1114 rotate_list((&c->very_dirty_list), rotateby);
1115 }
1116
1117 x = count_list(&c->dirty_list);
1118 if (x) {
1119 rotateby = pseudo_random % x;
1120 rotate_list((&c->dirty_list), rotateby);
1121 }
1122
1123 x = count_list(&c->erasable_list);
1124 if (x) {
1125 rotateby = pseudo_random % x;
1126 rotate_list((&c->erasable_list), rotateby);
1127 }
1128
1129 if (c->nr_erasing_blocks) {
1130 rotateby = pseudo_random % c->nr_erasing_blocks;
1131 rotate_list((&c->erase_pending_list), rotateby);
1132 }
1133
1134 if (c->nr_free_blocks) {
1135 rotateby = pseudo_random % c->nr_free_blocks;
1136 rotate_list((&c->free_list), rotateby);
1137 }
1138 }
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