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allow coexistance of N build and AC build.
[tomato.git] / release / src-rt-6.x / linux / linux-2.6 / fs / jffs2 / scan.c
blobcb8ef9220ff63ec82399342f5b7552611787f163
1 /*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright © 2001-2007 Red Hat, Inc.
5 *
6 * Created by David Woodhouse <dwmw2@infradead.org>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/sched.h>
14 #include <linux/slab.h>
15 #include <linux/mtd/mtd.h>
16 #include <linux/pagemap.h>
17 #include <linux/crc32.h>
18 #include <linux/compiler.h>
19 #include "nodelist.h"
20 #include "summary.h"
21 #include "debug.h"
22
23 #define DEFAULT_EMPTY_SCAN_SIZE 1024
24
25 #define noisy_printk(noise, args...) do { \
26 if (*(noise)) { \
27 printk(KERN_NOTICE args); \
28 (*(noise))--; \
29 if (!(*(noise))) { \
30 printk(KERN_NOTICE "Further such events for this erase block will not be printed\n"); \
31 } \
32 } \
33 } while(0)
34
35 static uint32_t pseudo_random;
36
37 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
38 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s);
39
40 /* These helper functions _must_ increase ofs and also do the dirty/used space accounting.
41 * Returning an error will abort the mount - bad checksums etc. should just mark the space
42 * as dirty.
43 */
44 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
45 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s);
46 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
47 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s);
48
49 static inline int min_free(struct jffs2_sb_info *c)
50 {
51 uint32_t min = 2 * sizeof(struct jffs2_raw_inode);
52 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
53 if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize)
54 return c->wbuf_pagesize;
55 #endif
56 return min;
57
58 }
59
60 static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) {
61 if (sector_size < DEFAULT_EMPTY_SCAN_SIZE)
62 return sector_size;
63 else
64 return DEFAULT_EMPTY_SCAN_SIZE;
65 }
66
67 static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
68 {
69 int ret;
70
71 if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
72 return ret;
73 if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size)))
74 return ret;
75 /* Turned wasted size into dirty, since we apparently
76 think it's recoverable now. */
77 jeb->dirty_size += jeb->wasted_size;
78 c->dirty_size += jeb->wasted_size;
79 c->wasted_size -= jeb->wasted_size;
80 jeb->wasted_size = 0;
81 if (VERYDIRTY(c, jeb->dirty_size)) {
82 list_add(&jeb->list, &c->very_dirty_list);
83 } else {
84 list_add(&jeb->list, &c->dirty_list);
85 }
86 return 0;
87 }
88
89 int jffs2_scan_medium(struct jffs2_sb_info *c)
90 {
91 int i, ret;
92 uint32_t empty_blocks = 0, bad_blocks = 0;
93 unsigned char *flashbuf = NULL;
94 uint32_t buf_size = 0;
95 struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
96 #ifndef __ECOS
97 size_t pointlen;
98
99 if (c->mtd->point) {
100 ret = c->mtd->point (c->mtd, 0, c->mtd->size, &pointlen, &flashbuf);
101 if (!ret && pointlen < c->mtd->size) {
102 /* Don't muck about if it won't let us point to the whole flash */
103 D1(printk(KERN_DEBUG "MTD point returned len too short: 0x%zx\n", pointlen));
104 c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size);
105 flashbuf = NULL;
106 }
107 if (ret)
108 D1(printk(KERN_DEBUG "MTD point failed %d\n", ret));
109 }
110 #endif
111 if (!flashbuf) {
112 /* For NAND it's quicker to read a whole eraseblock at a time,
113 apparently */
114 if (jffs2_cleanmarker_oob(c))
115 buf_size = c->sector_size;
116 else
117 buf_size = PAGE_SIZE;
118
119 /* Respect kmalloc limitations */
120 if (buf_size > 128*1024)
121 buf_size = 128*1024;
122
123 D1(printk(KERN_DEBUG "Allocating readbuf of %d bytes\n", buf_size));
124 flashbuf = kmalloc(buf_size, GFP_KERNEL);
125 if (!flashbuf)
126 return -ENOMEM;
127 }
128
129 if (jffs2_sum_active()) {
130 s = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL);
131 if (!s) {
132 kfree(flashbuf);
133 JFFS2_WARNING("Can't allocate memory for summary\n");
134 return -ENOMEM;
135 }
136 }
137
138 for (i=0; i<c->nr_blocks; i++) {
139 struct jffs2_eraseblock *jeb = &c->blocks[i];
140
141 cond_resched();
142
143 /* reset summary info for next eraseblock scan */
144 jffs2_sum_reset_collected(s);
145
146 if (c->flags & (1 << 7))
147 ret = BLK_STATE_ALLFF;
148 else
149 ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
150 buf_size, s);
151
152 if (ret < 0)
153 goto out;
154
155 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
156
157 /* Now decide which list to put it on */
158 switch(ret) {
159 case BLK_STATE_ALLFF:
160 /*
161 * Empty block. Since we can't be sure it
162 * was entirely erased, we just queue it for erase
163 * again. It will be marked as such when the erase
164 * is complete. Meanwhile we still count it as empty
165 * for later checks.
166 */
167 empty_blocks++;
168 list_add(&jeb->list, &c->erase_pending_list);
169 c->nr_erasing_blocks++;
170 break;
171
172 case BLK_STATE_CLEANMARKER:
173 /* Only a CLEANMARKER node is valid */
174 if (!jeb->dirty_size) {
175 /* It's actually free */
176 list_add(&jeb->list, &c->free_list);
177 c->nr_free_blocks++;
178 } else {
179 /* Dirt */
180 D1(printk(KERN_DEBUG "Adding all-dirty block at 0x%08x to erase_pending_list\n", jeb->offset));
181 list_add(&jeb->list, &c->erase_pending_list);
182 c->nr_erasing_blocks++;
183 }
184 break;
185
186 case BLK_STATE_CLEAN:
187 /* Full (or almost full) of clean data. Clean list */
188 list_add(&jeb->list, &c->clean_list);
189 break;
190
191 case BLK_STATE_PARTDIRTY:
192 /* Some data, but not full. Dirty list. */
193 /* We want to remember the block with most free space
194 and stick it in the 'nextblock' position to start writing to it. */
195 if (jeb->free_size > min_free(c) &&
196 (!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
197 /* Better candidate for the next writes to go to */
198 if (c->nextblock) {
199 ret = file_dirty(c, c->nextblock);
200 if (ret)
201 return ret;
202 /* deleting summary information of the old nextblock */
203 jffs2_sum_reset_collected(c->summary);
204 }
205 /* update collected summary information for the current nextblock */
206 jffs2_sum_move_collected(c, s);
207 D1(printk(KERN_DEBUG "jffs2_scan_medium(): new nextblock = 0x%08x\n", jeb->offset));
208 c->nextblock = jeb;
209 } else {
210 ret = file_dirty(c, jeb);
211 if (ret)
212 return ret;
213 }
214 break;
215
216 case BLK_STATE_ALLDIRTY:
217 /* Nothing valid - not even a clean marker. Needs erasing. */
218 /* For now we just put it on the erasing list. We'll start the erases later */
219 D1(printk(KERN_NOTICE "JFFS2: Erase block at 0x%08x is not formatted. It will be erased\n", jeb->offset));
220 list_add(&jeb->list, &c->erase_pending_list);
221 c->nr_erasing_blocks++;
222 break;
223
224 case BLK_STATE_BADBLOCK:
225 D1(printk(KERN_NOTICE "JFFS2: Block at 0x%08x is bad\n", jeb->offset));
226 list_add(&jeb->list, &c->bad_list);
227 c->bad_size += c->sector_size;
228 c->free_size -= c->sector_size;
229 bad_blocks++;
230 break;
231 default:
232 printk(KERN_WARNING "jffs2_scan_medium(): unknown block state\n");
233 BUG();
234 }
235 }
236
237 /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
238 if (c->nextblock && (c->nextblock->dirty_size)) {
239 c->nextblock->wasted_size += c->nextblock->dirty_size;
240 c->wasted_size += c->nextblock->dirty_size;
241 c->dirty_size -= c->nextblock->dirty_size;
242 c->nextblock->dirty_size = 0;
243 }
244 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
245 if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) {
246 /* If we're going to start writing into a block which already
247 contains data, and the end of the data isn't page-aligned,
248 skip a little and align it. */
249
250 uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize;
251
252 D1(printk(KERN_DEBUG "jffs2_scan_medium(): Skipping %d bytes in nextblock to ensure page alignment\n",
253 skip));
254 jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
255 jffs2_scan_dirty_space(c, c->nextblock, skip);
256 }
257 #endif
258 if (c->nr_erasing_blocks) {
259 if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) {
260 printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
261 printk(KERN_NOTICE "empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",empty_blocks,bad_blocks,c->nr_blocks);
262 ret = -EIO;
263 goto out;
264 }
265 jffs2_erase_pending_trigger(c);
266 }
267 ret = 0;
268 out:
269 if (buf_size)
270 kfree(flashbuf);
271 #ifndef __ECOS
272 else
273 c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size);
274 #endif
275 if (s)
276 kfree(s);
277
278 return ret;
279 }
280
281 static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf,
282 uint32_t ofs, uint32_t len)
283 {
284 int ret;
285 size_t retlen;
286
287 ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
288 if (ret) {
289 D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", len, ofs, ret));
290 return ret;
291 }
292 if (retlen < len) {
293 D1(printk(KERN_WARNING "Read at 0x%x gave only 0x%zx bytes\n", ofs, retlen));
294 return -EIO;
295 }
296 return 0;
297 }
298
299 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
300 {
301 if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
302 && (!jeb->first_node || !ref_next(jeb->first_node)) )
303 return BLK_STATE_CLEANMARKER;
304
305 /* move blocks with max 4 byte dirty space to cleanlist */
306 else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
307 c->dirty_size -= jeb->dirty_size;
308 c->wasted_size += jeb->dirty_size;
309 jeb->wasted_size += jeb->dirty_size;
310 jeb->dirty_size = 0;
311 return BLK_STATE_CLEAN;
312 } else if (jeb->used_size || jeb->unchecked_size)
313 return BLK_STATE_PARTDIRTY;
314 else
315 return BLK_STATE_ALLDIRTY;
316 }
317
318 #ifdef CONFIG_JFFS2_FS_XATTR
319 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
320 struct jffs2_raw_xattr *rx, uint32_t ofs,
321 struct jffs2_summary *s)
322 {
323 struct jffs2_xattr_datum *xd;
324 uint32_t xid, version, totlen, crc;
325 int err;
326
327 crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
328 if (crc != je32_to_cpu(rx->node_crc)) {
329 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
330 ofs, je32_to_cpu(rx->node_crc), crc);
331 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
332 return err;
333 return 0;
334 }
335
336 xid = je32_to_cpu(rx->xid);
337 version = je32_to_cpu(rx->version);
338
339 totlen = PAD(sizeof(struct jffs2_raw_xattr)
340 + rx->name_len + 1 + je16_to_cpu(rx->value_len));
341 if (totlen != je32_to_cpu(rx->totlen)) {
342 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
343 ofs, je32_to_cpu(rx->totlen), totlen);
344 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
345 return err;
346 return 0;
347 }
348
349 xd = jffs2_setup_xattr_datum(c, xid, version);
350 if (IS_ERR(xd))
351 return PTR_ERR(xd);
352
353 if (xd->version > version) {
354 struct jffs2_raw_node_ref *raw
355 = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL);
356 raw->next_in_ino = xd->node->next_in_ino;
357 xd->node->next_in_ino = raw;
358 } else {
359 xd->version = version;
360 xd->xprefix = rx->xprefix;
361 xd->name_len = rx->name_len;
362 xd->value_len = je16_to_cpu(rx->value_len);
363 xd->data_crc = je32_to_cpu(rx->data_crc);
364
365 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd);
366 }
367
368 if (jffs2_sum_active())
369 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
370 dbg_xattr("scaning xdatum at %#08x (xid=%u, version=%u)\n",
371 ofs, xd->xid, xd->version);
372 return 0;
373 }
374
375 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
376 struct jffs2_raw_xref *rr, uint32_t ofs,
377 struct jffs2_summary *s)
378 {
379 struct jffs2_xattr_ref *ref;
380 uint32_t crc;
381 int err;
382
383 crc = crc32(0, rr, sizeof(*rr) - 4);
384 if (crc != je32_to_cpu(rr->node_crc)) {
385 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
386 ofs, je32_to_cpu(rr->node_crc), crc);
387 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
388 return err;
389 return 0;
390 }
391
392 if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
393 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n",
394 ofs, je32_to_cpu(rr->totlen),
395 PAD(sizeof(struct jffs2_raw_xref)));
396 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
397 return err;
398 return 0;
399 }
400
401 ref = jffs2_alloc_xattr_ref();
402 if (!ref)
403 return -ENOMEM;
404
405 /* BEFORE jffs2_build_xattr_subsystem() called,
406 * and AFTER xattr_ref is marked as a dead xref,
407 * ref->xid is used to store 32bit xid, xd is not used
408 * ref->ino is used to store 32bit inode-number, ic is not used
409 * Thoes variables are declared as union, thus using those
410 * are exclusive. In a similar way, ref->next is temporarily
411 * used to chain all xattr_ref object. It's re-chained to
412 * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
413 */
414 ref->ino = je32_to_cpu(rr->ino);
415 ref->xid = je32_to_cpu(rr->xid);
416 ref->xseqno = je32_to_cpu(rr->xseqno);
417 if (ref->xseqno > c->highest_xseqno)
418 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
419 ref->next = c->xref_temp;
420 c->xref_temp = ref;
421
422 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref);
423
424 if (jffs2_sum_active())
425 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
426 dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
427 ofs, ref->xid, ref->ino);
428 return 0;
429 }
430 #endif
431
432 /* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
433 the flash, XIP-style */
434 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
435 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
436 struct jffs2_unknown_node *node;
437 struct jffs2_unknown_node crcnode;
438 uint32_t ofs, prevofs;
439 uint32_t hdr_crc, buf_ofs, buf_len;
440 int err;
441 int noise = 0;
442
443
444 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
445 int cleanmarkerfound = 0;
446 #endif
447
448 ofs = jeb->offset;
449 prevofs = jeb->offset - 1;
450
451 D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs));
452
453 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
454 if (jffs2_cleanmarker_oob(c)) {
455 int ret;
456
457 if (c->mtd->block_isbad(c->mtd, jeb->offset))
458 return BLK_STATE_BADBLOCK;
459
460 ret = jffs2_check_nand_cleanmarker(c, jeb);
461 D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret));
462
463 /* Even if it's not found, we still scan to see
464 if the block is empty. We use this information
465 to decide whether to erase it or not. */
466 switch (ret) {
467 case 0: cleanmarkerfound = 1; break;
468 case 1: break;
469 default: return ret;
470 }
471 }
472 #endif
473
474 if (jffs2_sum_active()) {
475 struct jffs2_sum_marker *sm;
476 void *sumptr = NULL;
477 uint32_t sumlen;
478
479 if (!buf_size) {
480 /* XIP case. Just look, point at the summary if it's there */
481 sm = (void *)buf + c->sector_size - sizeof(*sm);
482 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
483 sumptr = buf + je32_to_cpu(sm->offset);
484 sumlen = c->sector_size - je32_to_cpu(sm->offset);
485 }
486 } else {
487 /* If NAND flash, read a whole page of it. Else just the end */
488 if (c->wbuf_pagesize)
489 buf_len = c->wbuf_pagesize;
490 else
491 buf_len = sizeof(*sm);
492
493 /* Read as much as we want into the _end_ of the preallocated buffer */
494 err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len,
495 jeb->offset + c->sector_size - buf_len,
496 buf_len);
497 if (err)
498 return err;
499
500 sm = (void *)buf + buf_size - sizeof(*sm);
501 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
502 sumlen = c->sector_size - je32_to_cpu(sm->offset);
503 sumptr = buf + buf_size - sumlen;
504
505 /* Now, make sure the summary itself is available */
506 if (sumlen > buf_size) {
507 /* Need to kmalloc for this. */
508 sumptr = kmalloc(sumlen, GFP_KERNEL);
509 if (!sumptr)
510 return -ENOMEM;
511 memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
512 }
513 if (buf_len < sumlen) {
514 /* Need to read more so that the entire summary node is present */
515 err = jffs2_fill_scan_buf(c, sumptr,
516 jeb->offset + c->sector_size - sumlen,
517 sumlen - buf_len);
518 if (err)
519 return err;
520 }
521 }
522
523 }
524
525 if (sumptr) {
526 err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
527
528 if (buf_size && sumlen > buf_size)
529 kfree(sumptr);
530 /* If it returns with a real error, bail.
531 If it returns positive, that's a block classification
532 (i.e. BLK_STATE_xxx) so return that too.
533 If it returns zero, fall through to full scan. */
534 if (err)
535 return err;
536 }
537 }
538
539 buf_ofs = jeb->offset;
540
541 if (!buf_size) {
542 /* This is the XIP case -- we're reading _directly_ from the flash chip */
543 buf_len = c->sector_size;
544 } else {
545 buf_len = EMPTY_SCAN_SIZE(c->sector_size);
546 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
547 if (err)
548 return err;
549 }
550
551 if ((buf[0] == 0xde) &&
552 (buf[1] == 0xad) &&
553 (buf[2] == 0xc0) &&
554 (buf[3] == 0xde)) {
555 /* end of filesystem. erase everything after this point */
556 printk("%s(): End of filesystem marker found at 0x%x\n", __func__, jeb->offset);
557 c->flags |= (1 << 7);
558
559 return BLK_STATE_ALLFF;
560 }
561
562 /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
563 ofs = 0;
564
565 /* Scan only 4KiB of 0xFF before declaring it's empty */
566 while(ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
567 ofs += 4;
568
569 if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) {
570 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
571 if (jffs2_cleanmarker_oob(c)) {
572 /* scan oob, take care of cleanmarker */
573 int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
574 D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret));
575 switch (ret) {
576 case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
577 case 1: return BLK_STATE_ALLDIRTY;
578 default: return ret;
579 }
580 }
581 #endif
582 D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset));
583 if (c->cleanmarker_size == 0)
584 return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */
585 else
586 return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
587 }
588 if (ofs) {
589 D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset,
590 jeb->offset + ofs));
591 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
592 return err;
593 if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
594 return err;
595 }
596
597 /* Now ofs is a complete physical flash offset as it always was... */
598 ofs += jeb->offset;
599
600 noise = 10;
601
602 dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
603
604 scan_more:
605 while(ofs < jeb->offset + c->sector_size) {
606
607 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
608
609 /* Make sure there are node refs available for use */
610 err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
611 if (err)
612 return err;
613
614 cond_resched();
615
616 if (ofs & 3) {
617 printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs);
618 ofs = PAD(ofs);
619 continue;
620 }
621 if (ofs == prevofs) {
622 printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs);
623 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
624 return err;
625 ofs += 4;
626 continue;
627 }
628 prevofs = ofs;
629
630 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
631 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),
632 jeb->offset, c->sector_size, ofs, sizeof(*node)));
633 if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
634 return err;
635 break;
636 }
637
638 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
639 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
640 D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
641 sizeof(struct jffs2_unknown_node), buf_len, ofs));
642 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
643 if (err)
644 return err;
645 buf_ofs = ofs;
646 }
647
648 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
649
650 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
651 uint32_t inbuf_ofs;
652 uint32_t empty_start, scan_end;
653
654 empty_start = ofs;
655 ofs += 4;
656 scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len);
657
658 D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs));
659 more_empty:
660 inbuf_ofs = ofs - buf_ofs;
661 while (inbuf_ofs < scan_end) {
662 if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) {
663 printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n",
664 empty_start, ofs);
665 if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
666 return err;
667 goto scan_more;
668 }
669
670 inbuf_ofs+=4;
671 ofs += 4;
672 }
673 /* Ran off end. */
674 D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs));
675
676 /* If we're only checking the beginning of a block with a cleanmarker,
677 bail now */
678 if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
679 c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
680 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size)));
681 return BLK_STATE_CLEANMARKER;
682 }
683 if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */
684 scan_end = buf_len;
685 goto more_empty;
686 }
687
688 /* See how much more there is to read in this eraseblock... */
689 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
690 if (!buf_len) {
691 /* No more to read. Break out of main loop without marking
692 this range of empty space as dirty (because it's not) */
693 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n",
694 empty_start));
695 break;
696 }
697 /* point never reaches here */
698 scan_end = buf_len;
699 D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs));
700 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
701 if (err)
702 return err;
703 buf_ofs = ofs;
704 goto more_empty;
705 }
706
707 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
708 printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs);
709 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
710 return err;
711 ofs += 4;
712 continue;
713 }
714 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
715 D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs));
716 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
717 return err;
718 ofs += 4;
719 continue;
720 }
721 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
722 printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs);
723 printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n");
724 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
725 return err;
726 ofs += 4;
727 continue;
728 }
729 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
730 /* OK. We're out of possibilities. Whinge and move on */
731 noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
732 JFFS2_MAGIC_BITMASK, ofs,
733 je16_to_cpu(node->magic));
734 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
735 return err;
736 ofs += 4;
737 continue;
738 }
739 /* We seem to have a node of sorts. Check the CRC */
740 crcnode.magic = node->magic;
741 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
742 crcnode.totlen = node->totlen;
743 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
744
745 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
746 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",
747 ofs, je16_to_cpu(node->magic),
748 je16_to_cpu(node->nodetype),
749 je32_to_cpu(node->totlen),
750 je32_to_cpu(node->hdr_crc),
751 hdr_crc);
752 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
753 return err;
754 ofs += 4;
755 continue;
756 }
757
758 if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) {
759 /* Eep. Node goes over the end of the erase block. */
760 printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
761 ofs, je32_to_cpu(node->totlen));
762 printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
763 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
764 return err;
765 ofs += 4;
766 continue;
767 }
768
769 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
770 /* Wheee. This is an obsoleted node */
771 D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));
772 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
773 return err;
774 ofs += PAD(je32_to_cpu(node->totlen));
775 continue;
776 }
777
778 switch(je16_to_cpu(node->nodetype)) {
779 case JFFS2_NODETYPE_INODE:
780 if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
781 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
782 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
783 sizeof(struct jffs2_raw_inode), buf_len, ofs));
784 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
785 if (err)
786 return err;
787 buf_ofs = ofs;
788 node = (void *)buf;
789 }
790 err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
791 if (err) return err;
792 ofs += PAD(je32_to_cpu(node->totlen));
793 break;
794
795 case JFFS2_NODETYPE_DIRENT:
796 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
797 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
798 D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
799 je32_to_cpu(node->totlen), buf_len, ofs));
800 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
801 if (err)
802 return err;
803 buf_ofs = ofs;
804 node = (void *)buf;
805 }
806 err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
807 if (err) return err;
808 ofs += PAD(je32_to_cpu(node->totlen));
809 break;
810
811 #ifdef CONFIG_JFFS2_FS_XATTR
812 case JFFS2_NODETYPE_XATTR:
813 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
814 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
815 D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)"
816 " left to end of buf. Reading 0x%x at 0x%08x\n",
817 je32_to_cpu(node->totlen), buf_len, ofs));
818 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
819 if (err)
820 return err;
821 buf_ofs = ofs;
822 node = (void *)buf;
823 }
824 err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
825 if (err)
826 return err;
827 ofs += PAD(je32_to_cpu(node->totlen));
828 break;
829 case JFFS2_NODETYPE_XREF:
830 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
831 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
832 D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)"
833 " left to end of buf. Reading 0x%x at 0x%08x\n",
834 je32_to_cpu(node->totlen), buf_len, ofs));
835 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
836 if (err)
837 return err;
838 buf_ofs = ofs;
839 node = (void *)buf;
840 }
841 err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
842 if (err)
843 return err;
844 ofs += PAD(je32_to_cpu(node->totlen));
845 break;
846 #endif /* CONFIG_JFFS2_FS_XATTR */
847
848 case JFFS2_NODETYPE_CLEANMARKER:
849 D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs));
850 if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
851 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
852 ofs, je32_to_cpu(node->totlen), c->cleanmarker_size);
853 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
854 return err;
855 ofs += PAD(sizeof(struct jffs2_unknown_node));
856 } else if (jeb->first_node) {
857 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset);
858 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
859 return err;
860 ofs += PAD(sizeof(struct jffs2_unknown_node));
861 } else {
862 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
863
864 ofs += PAD(c->cleanmarker_size);
865 }
866 break;
867
868 case JFFS2_NODETYPE_PADDING:
869 if (jffs2_sum_active())
870 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
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 default:
877 switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
878 case JFFS2_FEATURE_ROCOMPAT:
879 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
880 c->flags |= JFFS2_SB_FLAG_RO;
881 if (!(jffs2_is_readonly(c)))
882 return -EROFS;
883 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
884 return err;
885 ofs += PAD(je32_to_cpu(node->totlen));
886 break;
887
888 case JFFS2_FEATURE_INCOMPAT:
889 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
890 return -EINVAL;
891
892 case JFFS2_FEATURE_RWCOMPAT_DELETE:
893 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
894 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
895 return err;
896 ofs += PAD(je32_to_cpu(node->totlen));
897 break;
898
899 case JFFS2_FEATURE_RWCOMPAT_COPY: {
900 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
901
902 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
903
904 /* We can't summarise nodes we don't grok */
905 jffs2_sum_disable_collecting(s);
906 ofs += PAD(je32_to_cpu(node->totlen));
907 break;
908 }
909 }
910 }
911 }
912
913 if (jffs2_sum_active()) {
914 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
915 dbg_summary("There is not enough space for "
916 "summary information, disabling for this jeb!\n");
917 jffs2_sum_disable_collecting(s);
918 }
919 }
920
921 D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
922 jeb->offset,jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size, jeb->wasted_size));
923
924 /* mark_node_obsolete can add to wasted !! */
925 if (jeb->wasted_size) {
926 jeb->dirty_size += jeb->wasted_size;
927 c->dirty_size += jeb->wasted_size;
928 c->wasted_size -= jeb->wasted_size;
929 jeb->wasted_size = 0;
930 }
931
932 return jffs2_scan_classify_jeb(c, jeb);
933 }
934
935 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
936 {
937 struct jffs2_inode_cache *ic;
938
939 ic = jffs2_get_ino_cache(c, ino);
940 if (ic)
941 return ic;
942
943 if (ino > c->highest_ino)
944 c->highest_ino = ino;
945
946 ic = jffs2_alloc_inode_cache();
947 if (!ic) {
948 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n");
949 return NULL;
950 }
951 memset(ic, 0, sizeof(*ic));
952
953 ic->ino = ino;
954 ic->nodes = (void *)ic;
955 jffs2_add_ino_cache(c, ic);
956 if (ino == 1)
957 ic->nlink = 1;
958 return ic;
959 }
960
961 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
962 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
963 {
964 struct jffs2_inode_cache *ic;
965 uint32_t crc, ino = je32_to_cpu(ri->ino);
966
967 D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs));
968
969 /* We do very little here now. Just check the ino# to which we should attribute
970 this node; we can do all the CRC checking etc. later. There's a tradeoff here --
971 we used to scan the flash once only, reading everything we want from it into
972 memory, then building all our in-core data structures and freeing the extra
973 information. Now we allow the first part of the mount to complete a lot quicker,
974 but we have to go _back_ to the flash in order to finish the CRC checking, etc.
975 Which means that the _full_ amount of time to get to proper write mode with GC
976 operational may actually be _longer_ than before. Sucks to be me. */
977
978 /* Check the node CRC in any case. */
979 crc = crc32(0, ri, sizeof(*ri)-8);
980 if (crc != je32_to_cpu(ri->node_crc)) {
981 printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on "
982 "node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
983 ofs, je32_to_cpu(ri->node_crc), crc);
984 /*
985 * We believe totlen because the CRC on the node
986 * _header_ was OK, just the node itself failed.
987 */
988 return jffs2_scan_dirty_space(c, jeb,
989 PAD(je32_to_cpu(ri->totlen)));
990 }
991
992 ic = jffs2_get_ino_cache(c, ino);
993 if (!ic) {
994 ic = jffs2_scan_make_ino_cache(c, ino);
995 if (!ic)
996 return -ENOMEM;
997 }
998
999 /* Wheee. It worked */
1000 jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
1001
1002 D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
1003 je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
1004 je32_to_cpu(ri->offset),
1005 je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)));
1006
1007 pseudo_random += je32_to_cpu(ri->version);
1008
1009 if (jffs2_sum_active()) {
1010 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
1011 }
1012
1013 return 0;
1014 }
1015
1016 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
1017 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
1018 {
1019 struct jffs2_full_dirent *fd;
1020 struct jffs2_inode_cache *ic;
1021 uint32_t crc;
1022 int err;
1023
1024 D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs));
1025
1026 /* We don't get here unless the node is still valid, so we don't have to
1027 mask in the ACCURATE bit any more. */
1028 crc = crc32(0, rd, sizeof(*rd)-8);
1029
1030 if (crc != je32_to_cpu(rd->node_crc)) {
1031 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1032 ofs, je32_to_cpu(rd->node_crc), crc);
1033 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1034 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1035 return err;
1036 return 0;
1037 }
1038
1039 pseudo_random += je32_to_cpu(rd->version);
1040
1041 fd = jffs2_alloc_full_dirent(rd->nsize+1);
1042 if (!fd) {
1043 return -ENOMEM;
1044 }
1045 memcpy(&fd->name, rd->name, rd->nsize);
1046 fd->name[rd->nsize] = 0;
1047
1048 crc = crc32(0, fd->name, rd->nsize);
1049 if (crc != je32_to_cpu(rd->name_crc)) {
1050 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1051 ofs, je32_to_cpu(rd->name_crc), crc);
1052 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino)));
1053 jffs2_free_full_dirent(fd);
1054 /* FIXME: Why do we believe totlen? */
1055 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1056 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1057 return err;
1058 return 0;
1059 }
1060 ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1061 if (!ic) {
1062 jffs2_free_full_dirent(fd);
1063 return -ENOMEM;
1064 }
1065
1066 fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd),
1067 PAD(je32_to_cpu(rd->totlen)), ic);
1068
1069 fd->next = NULL;
1070 fd->version = je32_to_cpu(rd->version);
1071 fd->ino = je32_to_cpu(rd->ino);
1072 fd->nhash = full_name_hash(fd->name, rd->nsize);
1073 fd->type = rd->type;
1074 jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1075
1076 if (jffs2_sum_active()) {
1077 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1078 }
1079
1080 return 0;
1081 }
1082
1083 static int count_list(struct list_head *l)
1084 {
1085 uint32_t count = 0;
1086 struct list_head *tmp;
1087
1088 list_for_each(tmp, l) {
1089 count++;
1090 }
1091 return count;
1092 }
1093
1094 /* Note: This breaks if list_empty(head). I don't care. You
1095 might, if you copy this code and use it elsewhere :) */
1096 static void rotate_list(struct list_head *head, uint32_t count)
1097 {
1098 struct list_head *n = head->next;
1099
1100 list_del(head);
1101 while(count--) {
1102 n = n->next;
1103 }
1104 list_add(head, n);
1105 }
1106
1107 void jffs2_rotate_lists(struct jffs2_sb_info *c)
1108 {
1109 uint32_t x;
1110 uint32_t rotateby;
1111
1112 x = count_list(&c->clean_list);
1113 if (x) {
1114 rotateby = pseudo_random % x;
1115 rotate_list((&c->clean_list), rotateby);
1116 }
1117
1118 x = count_list(&c->very_dirty_list);
1119 if (x) {
1120 rotateby = pseudo_random % x;
1121 rotate_list((&c->very_dirty_list), rotateby);
1122 }
1123
1124 x = count_list(&c->dirty_list);
1125 if (x) {
1126 rotateby = pseudo_random % x;
1127 rotate_list((&c->dirty_list), rotateby);
1128 }
1129
1130 x = count_list(&c->erasable_list);
1131 if (x) {
1132 rotateby = pseudo_random % x;
1133 rotate_list((&c->erasable_list), rotateby);
1134 }
1135
1136 if (c->nr_erasing_blocks) {
1137 rotateby = pseudo_random % c->nr_erasing_blocks;
1138 rotate_list((&c->erase_pending_list), rotateby);
1139 }
1140
1141 if (c->nr_free_blocks) {
1142 rotateby = pseudo_random % c->nr_free_blocks;
1143 rotate_list((&c->free_list), rotateby);
1144 }
1145 }
Tomato firmware and modifications.