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Merge tag 'writeback_for_v5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git...
[mirror_ubuntu-hirsute-kernel.git] / fs / jffs2 / scan.c
1 /*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright © 2001-2007 Red Hat, Inc.
5 *
6 * Created by David Woodhouse <dwmw2@infradead.org>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
10 */
11
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14 #include <linux/kernel.h>
15 #include <linux/sched.h>
16 #include <linux/slab.h>
17 #include <linux/mtd/mtd.h>
18 #include <linux/pagemap.h>
19 #include <linux/crc32.h>
20 #include <linux/compiler.h>
21 #include "nodelist.h"
22 #include "summary.h"
23 #include "debug.h"
24
25 #define DEFAULT_EMPTY_SCAN_SIZE 256
26
27 #define noisy_printk(noise, fmt, ...) \
28 do { \
29 if (*(noise)) { \
30 pr_notice(fmt, ##__VA_ARGS__); \
31 (*(noise))--; \
32 if (!(*(noise))) \
33 pr_notice("Further such events for this erase block will not be printed\n"); \
34 } \
35 } while (0)
36
37 static uint32_t pseudo_random;
38
39 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
40 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s);
41
42 /* These helper functions _must_ increase ofs and also do the dirty/used space accounting.
43 * Returning an error will abort the mount - bad checksums etc. should just mark the space
44 * as dirty.
45 */
46 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
47 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s);
48 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
49 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s);
50
51 static inline int min_free(struct jffs2_sb_info *c)
52 {
53 uint32_t min = 2 * sizeof(struct jffs2_raw_inode);
54 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
55 if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize)
56 return c->wbuf_pagesize;
57 #endif
58 return min;
59
60 }
61
62 static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) {
63 if (sector_size < DEFAULT_EMPTY_SCAN_SIZE)
64 return sector_size;
65 else
66 return DEFAULT_EMPTY_SCAN_SIZE;
67 }
68
69 static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
70 {
71 int ret;
72
73 if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
74 return ret;
75 if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size)))
76 return ret;
77 /* Turned wasted size into dirty, since we apparently
78 think it's recoverable now. */
79 jeb->dirty_size += jeb->wasted_size;
80 c->dirty_size += jeb->wasted_size;
81 c->wasted_size -= jeb->wasted_size;
82 jeb->wasted_size = 0;
83 if (VERYDIRTY(c, jeb->dirty_size)) {
84 list_add(&jeb->list, &c->very_dirty_list);
85 } else {
86 list_add(&jeb->list, &c->dirty_list);
87 }
88 return 0;
89 }
90
91 int jffs2_scan_medium(struct jffs2_sb_info *c)
92 {
93 int i, ret;
94 uint32_t empty_blocks = 0, bad_blocks = 0;
95 unsigned char *flashbuf = NULL;
96 uint32_t buf_size = 0;
97 struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
98 #ifndef __ECOS
99 size_t pointlen, try_size;
100
101 ret = mtd_point(c->mtd, 0, c->mtd->size, &pointlen,
102 (void **)&flashbuf, NULL);
103 if (!ret && pointlen < c->mtd->size) {
104 /* Don't muck about if it won't let us point to the whole flash */
105 jffs2_dbg(1, "MTD point returned len too short: 0x%zx\n",
106 pointlen);
107 mtd_unpoint(c->mtd, 0, pointlen);
108 flashbuf = NULL;
109 }
110 if (ret && ret != -EOPNOTSUPP)
111 jffs2_dbg(1, "MTD point failed %d\n", ret);
112 #endif
113 if (!flashbuf) {
114 /* For NAND it's quicker to read a whole eraseblock at a time,
115 apparently */
116 if (jffs2_cleanmarker_oob(c))
117 try_size = c->sector_size;
118 else
119 try_size = PAGE_SIZE;
120
121 jffs2_dbg(1, "Trying to allocate readbuf of %zu "
122 "bytes\n", try_size);
123
124 flashbuf = mtd_kmalloc_up_to(c->mtd, &try_size);
125 if (!flashbuf)
126 return -ENOMEM;
127
128 jffs2_dbg(1, "Allocated readbuf of %zu bytes\n",
129 try_size);
130
131 buf_size = (uint32_t)try_size;
132 }
133
134 if (jffs2_sum_active()) {
135 s = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL);
136 if (!s) {
137 JFFS2_WARNING("Can't allocate memory for summary\n");
138 ret = -ENOMEM;
139 goto out;
140 }
141 }
142
143 for (i=0; i<c->nr_blocks; i++) {
144 struct jffs2_eraseblock *jeb = &c->blocks[i];
145
146 cond_resched();
147
148 /* reset summary info for next eraseblock scan */
149 jffs2_sum_reset_collected(s);
150
151 ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
152 buf_size, s);
153
154 if (ret < 0)
155 goto out;
156
157 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
158
159 /* Now decide which list to put it on */
160 switch(ret) {
161 case BLK_STATE_ALLFF:
162 /*
163 * Empty block. Since we can't be sure it
164 * was entirely erased, we just queue it for erase
165 * again. It will be marked as such when the erase
166 * is complete. Meanwhile we still count it as empty
167 * for later checks.
168 */
169 empty_blocks++;
170 list_add(&jeb->list, &c->erase_pending_list);
171 c->nr_erasing_blocks++;
172 break;
173
174 case BLK_STATE_CLEANMARKER:
175 /* Only a CLEANMARKER node is valid */
176 if (!jeb->dirty_size) {
177 /* It's actually free */
178 list_add(&jeb->list, &c->free_list);
179 c->nr_free_blocks++;
180 } else {
181 /* Dirt */
182 jffs2_dbg(1, "Adding all-dirty block at 0x%08x to erase_pending_list\n",
183 jeb->offset);
184 list_add(&jeb->list, &c->erase_pending_list);
185 c->nr_erasing_blocks++;
186 }
187 break;
188
189 case BLK_STATE_CLEAN:
190 /* Full (or almost full) of clean data. Clean list */
191 list_add(&jeb->list, &c->clean_list);
192 break;
193
194 case BLK_STATE_PARTDIRTY:
195 /* Some data, but not full. Dirty list. */
196 /* We want to remember the block with most free space
197 and stick it in the 'nextblock' position to start writing to it. */
198 if (jeb->free_size > min_free(c) &&
199 (!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
200 /* Better candidate for the next writes to go to */
201 if (c->nextblock) {
202 ret = file_dirty(c, c->nextblock);
203 if (ret)
204 goto out;
205 /* deleting summary information of the old nextblock */
206 jffs2_sum_reset_collected(c->summary);
207 }
208 /* update collected summary information for the current nextblock */
209 jffs2_sum_move_collected(c, s);
210 jffs2_dbg(1, "%s(): new nextblock = 0x%08x\n",
211 __func__, jeb->offset);
212 c->nextblock = jeb;
213 } else {
214 ret = file_dirty(c, jeb);
215 if (ret)
216 goto out;
217 }
218 break;
219
220 case BLK_STATE_ALLDIRTY:
221 /* Nothing valid - not even a clean marker. Needs erasing. */
222 /* For now we just put it on the erasing list. We'll start the erases later */
223 jffs2_dbg(1, "Erase block at 0x%08x is not formatted. It will be erased\n",
224 jeb->offset);
225 list_add(&jeb->list, &c->erase_pending_list);
226 c->nr_erasing_blocks++;
227 break;
228
229 case BLK_STATE_BADBLOCK:
230 jffs2_dbg(1, "Block at 0x%08x is bad\n", jeb->offset);
231 list_add(&jeb->list, &c->bad_list);
232 c->bad_size += c->sector_size;
233 c->free_size -= c->sector_size;
234 bad_blocks++;
235 break;
236 default:
237 pr_warn("%s(): unknown block state\n", __func__);
238 BUG();
239 }
240 }
241
242 /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
243 if (c->nextblock && (c->nextblock->dirty_size)) {
244 c->nextblock->wasted_size += c->nextblock->dirty_size;
245 c->wasted_size += c->nextblock->dirty_size;
246 c->dirty_size -= c->nextblock->dirty_size;
247 c->nextblock->dirty_size = 0;
248 }
249 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
250 if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) {
251 /* If we're going to start writing into a block which already
252 contains data, and the end of the data isn't page-aligned,
253 skip a little and align it. */
254
255 uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize;
256
257 jffs2_dbg(1, "%s(): Skipping %d bytes in nextblock to ensure page alignment\n",
258 __func__, skip);
259 jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
260 jffs2_scan_dirty_space(c, c->nextblock, skip);
261 }
262 #endif
263 if (c->nr_erasing_blocks) {
264 if (!c->used_size && !c->unchecked_size &&
265 ((c->nr_free_blocks+empty_blocks+bad_blocks) != c->nr_blocks || bad_blocks == c->nr_blocks)) {
266 pr_notice("Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
267 pr_notice("empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",
268 empty_blocks, bad_blocks, c->nr_blocks);
269 ret = -EIO;
270 goto out;
271 }
272 spin_lock(&c->erase_completion_lock);
273 jffs2_garbage_collect_trigger(c);
274 spin_unlock(&c->erase_completion_lock);
275 }
276 ret = 0;
277 out:
278 if (buf_size)
279 kfree(flashbuf);
280 #ifndef __ECOS
281 else
282 mtd_unpoint(c->mtd, 0, c->mtd->size);
283 #endif
284 kfree(s);
285 return ret;
286 }
287
288 static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf,
289 uint32_t ofs, uint32_t len)
290 {
291 int ret;
292 size_t retlen;
293
294 ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
295 if (ret) {
296 jffs2_dbg(1, "mtd->read(0x%x bytes from 0x%x) returned %d\n",
297 len, ofs, ret);
298 return ret;
299 }
300 if (retlen < len) {
301 jffs2_dbg(1, "Read at 0x%x gave only 0x%zx bytes\n",
302 ofs, retlen);
303 return -EIO;
304 }
305 return 0;
306 }
307
308 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
309 {
310 if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
311 && (!jeb->first_node || !ref_next(jeb->first_node)) )
312 return BLK_STATE_CLEANMARKER;
313
314 /* move blocks with max 4 byte dirty space to cleanlist */
315 else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
316 c->dirty_size -= jeb->dirty_size;
317 c->wasted_size += jeb->dirty_size;
318 jeb->wasted_size += jeb->dirty_size;
319 jeb->dirty_size = 0;
320 return BLK_STATE_CLEAN;
321 } else if (jeb->used_size || jeb->unchecked_size)
322 return BLK_STATE_PARTDIRTY;
323 else
324 return BLK_STATE_ALLDIRTY;
325 }
326
327 #ifdef CONFIG_JFFS2_FS_XATTR
328 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
329 struct jffs2_raw_xattr *rx, uint32_t ofs,
330 struct jffs2_summary *s)
331 {
332 struct jffs2_xattr_datum *xd;
333 uint32_t xid, version, totlen, crc;
334 int err;
335
336 crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
337 if (crc != je32_to_cpu(rx->node_crc)) {
338 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
339 ofs, je32_to_cpu(rx->node_crc), crc);
340 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
341 return err;
342 return 0;
343 }
344
345 xid = je32_to_cpu(rx->xid);
346 version = je32_to_cpu(rx->version);
347
348 totlen = PAD(sizeof(struct jffs2_raw_xattr)
349 + rx->name_len + 1 + je16_to_cpu(rx->value_len));
350 if (totlen != je32_to_cpu(rx->totlen)) {
351 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
352 ofs, je32_to_cpu(rx->totlen), totlen);
353 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
354 return err;
355 return 0;
356 }
357
358 xd = jffs2_setup_xattr_datum(c, xid, version);
359 if (IS_ERR(xd))
360 return PTR_ERR(xd);
361
362 if (xd->version > version) {
363 struct jffs2_raw_node_ref *raw
364 = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL);
365 raw->next_in_ino = xd->node->next_in_ino;
366 xd->node->next_in_ino = raw;
367 } else {
368 xd->version = version;
369 xd->xprefix = rx->xprefix;
370 xd->name_len = rx->name_len;
371 xd->value_len = je16_to_cpu(rx->value_len);
372 xd->data_crc = je32_to_cpu(rx->data_crc);
373
374 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd);
375 }
376
377 if (jffs2_sum_active())
378 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
379 dbg_xattr("scanning xdatum at %#08x (xid=%u, version=%u)\n",
380 ofs, xd->xid, xd->version);
381 return 0;
382 }
383
384 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
385 struct jffs2_raw_xref *rr, uint32_t ofs,
386 struct jffs2_summary *s)
387 {
388 struct jffs2_xattr_ref *ref;
389 uint32_t crc;
390 int err;
391
392 crc = crc32(0, rr, sizeof(*rr) - 4);
393 if (crc != je32_to_cpu(rr->node_crc)) {
394 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
395 ofs, je32_to_cpu(rr->node_crc), crc);
396 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
397 return err;
398 return 0;
399 }
400
401 if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
402 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n",
403 ofs, je32_to_cpu(rr->totlen),
404 PAD(sizeof(struct jffs2_raw_xref)));
405 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
406 return err;
407 return 0;
408 }
409
410 ref = jffs2_alloc_xattr_ref();
411 if (!ref)
412 return -ENOMEM;
413
414 /* BEFORE jffs2_build_xattr_subsystem() called,
415 * and AFTER xattr_ref is marked as a dead xref,
416 * ref->xid is used to store 32bit xid, xd is not used
417 * ref->ino is used to store 32bit inode-number, ic is not used
418 * Thoes variables are declared as union, thus using those
419 * are exclusive. In a similar way, ref->next is temporarily
420 * used to chain all xattr_ref object. It's re-chained to
421 * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
422 */
423 ref->ino = je32_to_cpu(rr->ino);
424 ref->xid = je32_to_cpu(rr->xid);
425 ref->xseqno = je32_to_cpu(rr->xseqno);
426 if (ref->xseqno > c->highest_xseqno)
427 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
428 ref->next = c->xref_temp;
429 c->xref_temp = ref;
430
431 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref);
432
433 if (jffs2_sum_active())
434 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
435 dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
436 ofs, ref->xid, ref->ino);
437 return 0;
438 }
439 #endif
440
441 /* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
442 the flash, XIP-style */
443 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
444 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
445 struct jffs2_unknown_node *node;
446 struct jffs2_unknown_node crcnode;
447 uint32_t ofs, prevofs, max_ofs;
448 uint32_t hdr_crc, buf_ofs, buf_len;
449 int err;
450 int noise = 0;
451
452
453 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
454 int cleanmarkerfound = 0;
455 #endif
456
457 ofs = jeb->offset;
458 prevofs = jeb->offset - 1;
459
460 jffs2_dbg(1, "%s(): Scanning block at 0x%x\n", __func__, ofs);
461
462 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
463 if (jffs2_cleanmarker_oob(c)) {
464 int ret;
465
466 if (mtd_block_isbad(c->mtd, jeb->offset))
467 return BLK_STATE_BADBLOCK;
468
469 ret = jffs2_check_nand_cleanmarker(c, jeb);
470 jffs2_dbg(2, "jffs_check_nand_cleanmarker returned %d\n", ret);
471
472 /* Even if it's not found, we still scan to see
473 if the block is empty. We use this information
474 to decide whether to erase it or not. */
475 switch (ret) {
476 case 0: cleanmarkerfound = 1; break;
477 case 1: break;
478 default: return ret;
479 }
480 }
481 #endif
482
483 if (jffs2_sum_active()) {
484 struct jffs2_sum_marker *sm;
485 void *sumptr = NULL;
486 uint32_t sumlen;
487
488 if (!buf_size) {
489 /* XIP case. Just look, point at the summary if it's there */
490 sm = (void *)buf + c->sector_size - sizeof(*sm);
491 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
492 sumptr = buf + je32_to_cpu(sm->offset);
493 sumlen = c->sector_size - je32_to_cpu(sm->offset);
494 }
495 } else {
496 /* If NAND flash, read a whole page of it. Else just the end */
497 if (c->wbuf_pagesize)
498 buf_len = c->wbuf_pagesize;
499 else
500 buf_len = sizeof(*sm);
501
502 /* Read as much as we want into the _end_ of the preallocated buffer */
503 err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len,
504 jeb->offset + c->sector_size - buf_len,
505 buf_len);
506 if (err)
507 return err;
508
509 sm = (void *)buf + buf_size - sizeof(*sm);
510 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
511 sumlen = c->sector_size - je32_to_cpu(sm->offset);
512 sumptr = buf + buf_size - sumlen;
513
514 /* sm->offset maybe wrong but MAGIC maybe right */
515 if (sumlen > c->sector_size)
516 goto full_scan;
517
518 /* Now, make sure the summary itself is available */
519 if (sumlen > buf_size) {
520 /* Need to kmalloc for this. */
521 sumptr = kmalloc(sumlen, GFP_KERNEL);
522 if (!sumptr)
523 return -ENOMEM;
524 memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
525 }
526 if (buf_len < sumlen) {
527 /* Need to read more so that the entire summary node is present */
528 err = jffs2_fill_scan_buf(c, sumptr,
529 jeb->offset + c->sector_size - sumlen,
530 sumlen - buf_len);
531 if (err) {
532 if (sumlen > buf_size)
533 kfree(sumptr);
534 return err;
535 }
536 }
537 }
538
539 }
540
541 if (sumptr) {
542 err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
543
544 if (buf_size && sumlen > buf_size)
545 kfree(sumptr);
546 /* If it returns with a real error, bail.
547 If it returns positive, that's a block classification
548 (i.e. BLK_STATE_xxx) so return that too.
549 If it returns zero, fall through to full scan. */
550 if (err)
551 return err;
552 }
553 }
554
555 full_scan:
556 buf_ofs = jeb->offset;
557
558 if (!buf_size) {
559 /* This is the XIP case -- we're reading _directly_ from the flash chip */
560 buf_len = c->sector_size;
561 } else {
562 buf_len = EMPTY_SCAN_SIZE(c->sector_size);
563 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
564 if (err)
565 return err;
566 }
567
568 /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
569 ofs = 0;
570 max_ofs = EMPTY_SCAN_SIZE(c->sector_size);
571 /* Scan only EMPTY_SCAN_SIZE of 0xFF before declaring it's empty */
572 while(ofs < max_ofs && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
573 ofs += 4;
574
575 if (ofs == max_ofs) {
576 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
577 if (jffs2_cleanmarker_oob(c)) {
578 /* scan oob, take care of cleanmarker */
579 int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
580 jffs2_dbg(2, "jffs2_check_oob_empty returned %d\n",
581 ret);
582 switch (ret) {
583 case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
584 case 1: return BLK_STATE_ALLDIRTY;
585 default: return ret;
586 }
587 }
588 #endif
589 jffs2_dbg(1, "Block at 0x%08x is empty (erased)\n",
590 jeb->offset);
591 if (c->cleanmarker_size == 0)
592 return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */
593 else
594 return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
595 }
596 if (ofs) {
597 jffs2_dbg(1, "Free space at %08x ends at %08x\n", jeb->offset,
598 jeb->offset + ofs);
599 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
600 return err;
601 if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
602 return err;
603 }
604
605 /* Now ofs is a complete physical flash offset as it always was... */
606 ofs += jeb->offset;
607
608 noise = 10;
609
610 dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
611
612 scan_more:
613 while(ofs < jeb->offset + c->sector_size) {
614
615 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
616
617 /* Make sure there are node refs available for use */
618 err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
619 if (err)
620 return err;
621
622 cond_resched();
623
624 if (ofs & 3) {
625 pr_warn("Eep. ofs 0x%08x not word-aligned!\n", ofs);
626 ofs = PAD(ofs);
627 continue;
628 }
629 if (ofs == prevofs) {
630 pr_warn("ofs 0x%08x has already been seen. Skipping\n",
631 ofs);
632 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
633 return err;
634 ofs += 4;
635 continue;
636 }
637 prevofs = ofs;
638
639 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
640 jffs2_dbg(1, "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n",
641 sizeof(struct jffs2_unknown_node),
642 jeb->offset, c->sector_size, ofs,
643 sizeof(*node));
644 if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
645 return err;
646 break;
647 }
648
649 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
650 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
651 jffs2_dbg(1, "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
652 sizeof(struct jffs2_unknown_node),
653 buf_len, ofs);
654 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
655 if (err)
656 return err;
657 buf_ofs = ofs;
658 }
659
660 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
661
662 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
663 uint32_t inbuf_ofs;
664 uint32_t empty_start, scan_end;
665
666 empty_start = ofs;
667 ofs += 4;
668 scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len);
669
670 jffs2_dbg(1, "Found empty flash at 0x%08x\n", ofs);
671 more_empty:
672 inbuf_ofs = ofs - buf_ofs;
673 while (inbuf_ofs < scan_end) {
674 if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) {
675 pr_warn("Empty flash at 0x%08x ends at 0x%08x\n",
676 empty_start, ofs);
677 if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
678 return err;
679 goto scan_more;
680 }
681
682 inbuf_ofs+=4;
683 ofs += 4;
684 }
685 /* Ran off end. */
686 jffs2_dbg(1, "Empty flash to end of buffer at 0x%08x\n",
687 ofs);
688
689 /* If we're only checking the beginning of a block with a cleanmarker,
690 bail now */
691 if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
692 c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
693 jffs2_dbg(1, "%d bytes at start of block seems clean... assuming all clean\n",
694 EMPTY_SCAN_SIZE(c->sector_size));
695 return BLK_STATE_CLEANMARKER;
696 }
697 if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */
698 scan_end = buf_len;
699 goto more_empty;
700 }
701
702 /* See how much more there is to read in this eraseblock... */
703 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
704 if (!buf_len) {
705 /* No more to read. Break out of main loop without marking
706 this range of empty space as dirty (because it's not) */
707 jffs2_dbg(1, "Empty flash at %08x runs to end of block. Treating as free_space\n",
708 empty_start);
709 break;
710 }
711 /* point never reaches here */
712 scan_end = buf_len;
713 jffs2_dbg(1, "Reading another 0x%x at 0x%08x\n",
714 buf_len, ofs);
715 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
716 if (err)
717 return err;
718 buf_ofs = ofs;
719 goto more_empty;
720 }
721
722 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
723 pr_warn("Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n",
724 ofs);
725 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
726 return err;
727 ofs += 4;
728 continue;
729 }
730 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
731 jffs2_dbg(1, "Dirty bitmask at 0x%08x\n", ofs);
732 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
733 return err;
734 ofs += 4;
735 continue;
736 }
737 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
738 pr_warn("Old JFFS2 bitmask found at 0x%08x\n", ofs);
739 pr_warn("You cannot use older JFFS2 filesystems with newer kernels\n");
740 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
741 return err;
742 ofs += 4;
743 continue;
744 }
745 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
746 /* OK. We're out of possibilities. Whinge and move on */
747 noisy_printk(&noise, "%s(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
748 __func__,
749 JFFS2_MAGIC_BITMASK, ofs,
750 je16_to_cpu(node->magic));
751 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
752 return err;
753 ofs += 4;
754 continue;
755 }
756 /* We seem to have a node of sorts. Check the CRC */
757 crcnode.magic = node->magic;
758 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
759 crcnode.totlen = node->totlen;
760 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
761
762 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
763 noisy_printk(&noise, "%s(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n",
764 __func__,
765 ofs, je16_to_cpu(node->magic),
766 je16_to_cpu(node->nodetype),
767 je32_to_cpu(node->totlen),
768 je32_to_cpu(node->hdr_crc),
769 hdr_crc);
770 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
771 return err;
772 ofs += 4;
773 continue;
774 }
775
776 if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) {
777 /* Eep. Node goes over the end of the erase block. */
778 pr_warn("Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
779 ofs, je32_to_cpu(node->totlen));
780 pr_warn("Perhaps the file system was created with the wrong erase size?\n");
781 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
782 return err;
783 ofs += 4;
784 continue;
785 }
786
787 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
788 /* Wheee. This is an obsoleted node */
789 jffs2_dbg(2, "Node at 0x%08x is obsolete. Skipping\n",
790 ofs);
791 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
792 return err;
793 ofs += PAD(je32_to_cpu(node->totlen));
794 continue;
795 }
796
797 switch(je16_to_cpu(node->nodetype)) {
798 case JFFS2_NODETYPE_INODE:
799 if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
800 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
801 jffs2_dbg(1, "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
802 sizeof(struct jffs2_raw_inode),
803 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_inode_node(c, jeb, (void *)node, ofs, s);
811 if (err) return err;
812 ofs += PAD(je32_to_cpu(node->totlen));
813 break;
814
815 case JFFS2_NODETYPE_DIRENT:
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 jffs2_dbg(1, "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
819 je32_to_cpu(node->totlen), buf_len,
820 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_dirent_node(c, jeb, (void *)node, ofs, s);
828 if (err) return err;
829 ofs += PAD(je32_to_cpu(node->totlen));
830 break;
831
832 #ifdef CONFIG_JFFS2_FS_XATTR
833 case JFFS2_NODETYPE_XATTR:
834 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
835 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
836 jffs2_dbg(1, "Fewer than %d bytes (xattr node) left to end of buf. Reading 0x%x at 0x%08x\n",
837 je32_to_cpu(node->totlen), buf_len,
838 ofs);
839 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
840 if (err)
841 return err;
842 buf_ofs = ofs;
843 node = (void *)buf;
844 }
845 err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
846 if (err)
847 return err;
848 ofs += PAD(je32_to_cpu(node->totlen));
849 break;
850 case JFFS2_NODETYPE_XREF:
851 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
852 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
853 jffs2_dbg(1, "Fewer than %d bytes (xref node) left to end of buf. Reading 0x%x at 0x%08x\n",
854 je32_to_cpu(node->totlen), buf_len,
855 ofs);
856 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
857 if (err)
858 return err;
859 buf_ofs = ofs;
860 node = (void *)buf;
861 }
862 err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
863 if (err)
864 return err;
865 ofs += PAD(je32_to_cpu(node->totlen));
866 break;
867 #endif /* CONFIG_JFFS2_FS_XATTR */
868
869 case JFFS2_NODETYPE_CLEANMARKER:
870 jffs2_dbg(1, "CLEANMARKER node found at 0x%08x\n", ofs);
871 if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
872 pr_notice("CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
873 ofs, je32_to_cpu(node->totlen),
874 c->cleanmarker_size);
875 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
876 return err;
877 ofs += PAD(sizeof(struct jffs2_unknown_node));
878 } else if (jeb->first_node) {
879 pr_notice("CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n",
880 ofs, jeb->offset);
881 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
882 return err;
883 ofs += PAD(sizeof(struct jffs2_unknown_node));
884 } else {
885 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
886
887 ofs += PAD(c->cleanmarker_size);
888 }
889 break;
890
891 case JFFS2_NODETYPE_PADDING:
892 if (jffs2_sum_active())
893 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
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 default:
900 switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
901 case JFFS2_FEATURE_ROCOMPAT:
902 pr_notice("Read-only compatible feature node (0x%04x) found at offset 0x%08x\n",
903 je16_to_cpu(node->nodetype), ofs);
904 c->flags |= JFFS2_SB_FLAG_RO;
905 if (!(jffs2_is_readonly(c)))
906 return -EROFS;
907 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
908 return err;
909 ofs += PAD(je32_to_cpu(node->totlen));
910 break;
911
912 case JFFS2_FEATURE_INCOMPAT:
913 pr_notice("Incompatible feature node (0x%04x) found at offset 0x%08x\n",
914 je16_to_cpu(node->nodetype), ofs);
915 return -EINVAL;
916
917 case JFFS2_FEATURE_RWCOMPAT_DELETE:
918 jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n",
919 je16_to_cpu(node->nodetype), ofs);
920 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
921 return err;
922 ofs += PAD(je32_to_cpu(node->totlen));
923 break;
924
925 case JFFS2_FEATURE_RWCOMPAT_COPY: {
926 jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n",
927 je16_to_cpu(node->nodetype), ofs);
928
929 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
930
931 /* We can't summarise nodes we don't grok */
932 jffs2_sum_disable_collecting(s);
933 ofs += PAD(je32_to_cpu(node->totlen));
934 break;
935 }
936 }
937 }
938 }
939
940 if (jffs2_sum_active()) {
941 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
942 dbg_summary("There is not enough space for "
943 "summary information, disabling for this jeb!\n");
944 jffs2_sum_disable_collecting(s);
945 }
946 }
947
948 jffs2_dbg(1, "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
949 jeb->offset, jeb->free_size, jeb->dirty_size,
950 jeb->unchecked_size, jeb->used_size, jeb->wasted_size);
951
952 /* mark_node_obsolete can add to wasted !! */
953 if (jeb->wasted_size) {
954 jeb->dirty_size += jeb->wasted_size;
955 c->dirty_size += jeb->wasted_size;
956 c->wasted_size -= jeb->wasted_size;
957 jeb->wasted_size = 0;
958 }
959
960 return jffs2_scan_classify_jeb(c, jeb);
961 }
962
963 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
964 {
965 struct jffs2_inode_cache *ic;
966
967 ic = jffs2_get_ino_cache(c, ino);
968 if (ic)
969 return ic;
970
971 if (ino > c->highest_ino)
972 c->highest_ino = ino;
973
974 ic = jffs2_alloc_inode_cache();
975 if (!ic) {
976 pr_notice("%s(): allocation of inode cache failed\n", __func__);
977 return NULL;
978 }
979 memset(ic, 0, sizeof(*ic));
980
981 ic->ino = ino;
982 ic->nodes = (void *)ic;
983 jffs2_add_ino_cache(c, ic);
984 if (ino == 1)
985 ic->pino_nlink = 1;
986 return ic;
987 }
988
989 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
990 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
991 {
992 struct jffs2_inode_cache *ic;
993 uint32_t crc, ino = je32_to_cpu(ri->ino);
994
995 jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs);
996
997 /* We do very little here now. Just check the ino# to which we should attribute
998 this node; we can do all the CRC checking etc. later. There's a tradeoff here --
999 we used to scan the flash once only, reading everything we want from it into
1000 memory, then building all our in-core data structures and freeing the extra
1001 information. Now we allow the first part of the mount to complete a lot quicker,
1002 but we have to go _back_ to the flash in order to finish the CRC checking, etc.
1003 Which means that the _full_ amount of time to get to proper write mode with GC
1004 operational may actually be _longer_ than before. Sucks to be me. */
1005
1006 /* Check the node CRC in any case. */
1007 crc = crc32(0, ri, sizeof(*ri)-8);
1008 if (crc != je32_to_cpu(ri->node_crc)) {
1009 pr_notice("%s(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1010 __func__, ofs, je32_to_cpu(ri->node_crc), crc);
1011 /*
1012 * We believe totlen because the CRC on the node
1013 * _header_ was OK, just the node itself failed.
1014 */
1015 return jffs2_scan_dirty_space(c, jeb,
1016 PAD(je32_to_cpu(ri->totlen)));
1017 }
1018
1019 ic = jffs2_get_ino_cache(c, ino);
1020 if (!ic) {
1021 ic = jffs2_scan_make_ino_cache(c, ino);
1022 if (!ic)
1023 return -ENOMEM;
1024 }
1025
1026 /* Wheee. It worked */
1027 jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
1028
1029 jffs2_dbg(1, "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
1030 je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
1031 je32_to_cpu(ri->offset),
1032 je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize));
1033
1034 pseudo_random += je32_to_cpu(ri->version);
1035
1036 if (jffs2_sum_active()) {
1037 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
1038 }
1039
1040 return 0;
1041 }
1042
1043 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
1044 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
1045 {
1046 struct jffs2_full_dirent *fd;
1047 struct jffs2_inode_cache *ic;
1048 uint32_t checkedlen;
1049 uint32_t crc;
1050 int err;
1051
1052 jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs);
1053
1054 /* We don't get here unless the node is still valid, so we don't have to
1055 mask in the ACCURATE bit any more. */
1056 crc = crc32(0, rd, sizeof(*rd)-8);
1057
1058 if (crc != je32_to_cpu(rd->node_crc)) {
1059 pr_notice("%s(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1060 __func__, ofs, je32_to_cpu(rd->node_crc), crc);
1061 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1062 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1063 return err;
1064 return 0;
1065 }
1066
1067 pseudo_random += je32_to_cpu(rd->version);
1068
1069 /* Should never happen. Did. (OLPC trac #4184)*/
1070 checkedlen = strnlen(rd->name, rd->nsize);
1071 if (checkedlen < rd->nsize) {
1072 pr_err("Dirent at %08x has zeroes in name. Truncating to %d chars\n",
1073 ofs, checkedlen);
1074 }
1075 fd = jffs2_alloc_full_dirent(checkedlen+1);
1076 if (!fd) {
1077 return -ENOMEM;
1078 }
1079 memcpy(&fd->name, rd->name, checkedlen);
1080 fd->name[checkedlen] = 0;
1081
1082 crc = crc32(0, fd->name, rd->nsize);
1083 if (crc != je32_to_cpu(rd->name_crc)) {
1084 pr_notice("%s(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1085 __func__, ofs, je32_to_cpu(rd->name_crc), crc);
1086 jffs2_dbg(1, "Name for which CRC failed is (now) '%s', ino #%d\n",
1087 fd->name, je32_to_cpu(rd->ino));
1088 jffs2_free_full_dirent(fd);
1089 /* FIXME: Why do we believe totlen? */
1090 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1091 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1092 return err;
1093 return 0;
1094 }
1095 ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1096 if (!ic) {
1097 jffs2_free_full_dirent(fd);
1098 return -ENOMEM;
1099 }
1100
1101 fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd),
1102 PAD(je32_to_cpu(rd->totlen)), ic);
1103
1104 fd->next = NULL;
1105 fd->version = je32_to_cpu(rd->version);
1106 fd->ino = je32_to_cpu(rd->ino);
1107 fd->nhash = full_name_hash(NULL, fd->name, checkedlen);
1108 fd->type = rd->type;
1109 jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1110
1111 if (jffs2_sum_active()) {
1112 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1113 }
1114
1115 return 0;
1116 }
1117
1118 static int count_list(struct list_head *l)
1119 {
1120 uint32_t count = 0;
1121 struct list_head *tmp;
1122
1123 list_for_each(tmp, l) {
1124 count++;
1125 }
1126 return count;
1127 }
1128
1129 /* Note: This breaks if list_empty(head). I don't care. You
1130 might, if you copy this code and use it elsewhere :) */
1131 static void rotate_list(struct list_head *head, uint32_t count)
1132 {
1133 struct list_head *n = head->next;
1134
1135 list_del(head);
1136 while(count--) {
1137 n = n->next;
1138 }
1139 list_add(head, n);
1140 }
1141
1142 void jffs2_rotate_lists(struct jffs2_sb_info *c)
1143 {
1144 uint32_t x;
1145 uint32_t rotateby;
1146
1147 x = count_list(&c->clean_list);
1148 if (x) {
1149 rotateby = pseudo_random % x;
1150 rotate_list((&c->clean_list), rotateby);
1151 }
1152
1153 x = count_list(&c->very_dirty_list);
1154 if (x) {
1155 rotateby = pseudo_random % x;
1156 rotate_list((&c->very_dirty_list), rotateby);
1157 }
1158
1159 x = count_list(&c->dirty_list);
1160 if (x) {
1161 rotateby = pseudo_random % x;
1162 rotate_list((&c->dirty_list), rotateby);
1163 }
1164
1165 x = count_list(&c->erasable_list);
1166 if (x) {
1167 rotateby = pseudo_random % x;
1168 rotate_list((&c->erasable_list), rotateby);
1169 }
1170
1171 if (c->nr_erasing_blocks) {
1172 rotateby = pseudo_random % c->nr_erasing_blocks;
1173 rotate_list((&c->erase_pending_list), rotateby);
1174 }
1175
1176 if (c->nr_free_blocks) {
1177 rotateby = pseudo_random % c->nr_free_blocks;
1178 rotate_list((&c->free_list), rotateby);
1179 }
1180 }
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