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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 256
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
35static uint32_t pseudo_random;
36
37static 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 */
44static 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);
46static 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
49static 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
60static 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
67static 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
89int 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, try_size;
98
99 if (c->mtd->point) {
100 ret = c->mtd->point(c->mtd, 0, c->mtd->size, &pointlen,
101 (void **)&flashbuf, NULL);
102 if (!ret && pointlen < c->mtd->size) {
103 /* Don't muck about if it won't let us point to the whole flash */
104 D1(printk(KERN_DEBUG "MTD point returned len too short: 0x%zx\n", pointlen));
105 c->mtd->unpoint(c->mtd, 0, pointlen);
106 flashbuf = NULL;
107 }
108 if (ret)
109 D1(printk(KERN_DEBUG "MTD point failed %d\n", ret));
110 }
111#endif
112 if (!flashbuf) {
113 /* For NAND it's quicker to read a whole eraseblock at a time,
114 apparently */
115 if (jffs2_cleanmarker_oob(c))
116 try_size = c->sector_size;
117 else
118 try_size = PAGE_SIZE;
119
120 D1(printk(KERN_DEBUG "Trying to allocate readbuf of %zu "
121 "bytes\n", try_size));
122
123 flashbuf = mtd_kmalloc_up_to(c->mtd, &try_size);
124 if (!flashbuf)
125 return -ENOMEM;
126
127 D1(printk(KERN_DEBUG "Allocated readbuf of %zu bytes\n",
128 try_size));
129
130 buf_size = (uint32_t)try_size;
131 }
132
133 if (jffs2_sum_active()) {
134 s = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL);
135 if (!s) {
136 JFFS2_WARNING("Can't allocate memory for summary\n");
137 ret = -ENOMEM;
138 goto out;
139 }
140 }
141
142 for (i=0; i<c->nr_blocks; i++) {
143 struct jffs2_eraseblock *jeb = &c->blocks[i];
144
145 cond_resched();
146
147 /* reset summary info for next eraseblock scan */
148 jffs2_sum_reset_collected(s);
149
150 ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
151 buf_size, s);
152
153 if (ret < 0)
154 goto out;
155
156 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
157
158 /* Now decide which list to put it on */
159 switch(ret) {
160 case BLK_STATE_ALLFF:
161 /*
162 * Empty block. Since we can't be sure it
163 * was entirely erased, we just queue it for erase
164 * again. It will be marked as such when the erase
165 * is complete. Meanwhile we still count it as empty
166 * for later checks.
167 */
168 empty_blocks++;
169 list_add(&jeb->list, &c->erase_pending_list);
170 c->nr_erasing_blocks++;
171 break;
172
173 case BLK_STATE_CLEANMARKER:
174 /* Only a CLEANMARKER node is valid */
175 if (!jeb->dirty_size) {
176 /* It's actually free */
177 list_add(&jeb->list, &c->free_list);
178 c->nr_free_blocks++;
179 } else {
180 /* Dirt */
181 D1(printk(KERN_DEBUG "Adding all-dirty block at 0x%08x to erase_pending_list\n", jeb->offset));
182 list_add(&jeb->list, &c->erase_pending_list);
183 c->nr_erasing_blocks++;
184 }
185 break;
186
187 case BLK_STATE_CLEAN:
188 /* Full (or almost full) of clean data. Clean list */
189 list_add(&jeb->list, &c->clean_list);
190 break;
191
192 case BLK_STATE_PARTDIRTY:
193 /* Some data, but not full. Dirty list. */
194 /* We want to remember the block with most free space
195 and stick it in the 'nextblock' position to start writing to it. */
196 if (jeb->free_size > min_free(c) &&
197 (!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
198 /* Better candidate for the next writes to go to */
199 if (c->nextblock) {
200 ret = file_dirty(c, c->nextblock);
201 if (ret)
202 goto out;
203 /* deleting summary information of the old nextblock */
204 jffs2_sum_reset_collected(c->summary);
205 }
206 /* update collected summary information for the current nextblock */
207 jffs2_sum_move_collected(c, s);
208 D1(printk(KERN_DEBUG "jffs2_scan_medium(): new nextblock = 0x%08x\n", jeb->offset));
209 c->nextblock = jeb;
210 } else {
211 ret = file_dirty(c, jeb);
212 if (ret)
213 goto out;
214 }
215 break;
216
217 case BLK_STATE_ALLDIRTY:
218 /* Nothing valid - not even a clean marker. Needs erasing. */
219 /* For now we just put it on the erasing list. We'll start the erases later */
220 D1(printk(KERN_NOTICE "JFFS2: Erase block at 0x%08x is not formatted. It will be erased\n", jeb->offset));
221 list_add(&jeb->list, &c->erase_pending_list);
222 c->nr_erasing_blocks++;
223 break;
224
225 case BLK_STATE_BADBLOCK:
226 D1(printk(KERN_NOTICE "JFFS2: Block at 0x%08x is bad\n", jeb->offset));
227 list_add(&jeb->list, &c->bad_list);
228 c->bad_size += c->sector_size;
229 c->free_size -= c->sector_size;
230 bad_blocks++;
231 break;
232 default:
233 printk(KERN_WARNING "jffs2_scan_medium(): unknown block state\n");
234 BUG();
235 }
236 }
237
238 /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
239 if (c->nextblock && (c->nextblock->dirty_size)) {
240 c->nextblock->wasted_size += c->nextblock->dirty_size;
241 c->wasted_size += c->nextblock->dirty_size;
242 c->dirty_size -= c->nextblock->dirty_size;
243 c->nextblock->dirty_size = 0;
244 }
245#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
246 if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) {
247 /* If we're going to start writing into a block which already
248 contains data, and the end of the data isn't page-aligned,
249 skip a little and align it. */
250
251 uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize;
252
253 D1(printk(KERN_DEBUG "jffs2_scan_medium(): Skipping %d bytes in nextblock to ensure page alignment\n",
254 skip));
255 jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
256 jffs2_scan_dirty_space(c, c->nextblock, skip);
257 }
258#endif
259 if (c->nr_erasing_blocks) {
260 if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) {
261 printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
262 printk(KERN_NOTICE "empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",empty_blocks,bad_blocks,c->nr_blocks);
263 ret = -EIO;
264 goto out;
265 }
266 spin_lock(&c->erase_completion_lock);
267 jffs2_garbage_collect_trigger(c);
268 spin_unlock(&c->erase_completion_lock);
269 }
270 ret = 0;
271 out:
272 if (buf_size)
273 kfree(flashbuf);
274#ifndef __ECOS
275 else
276 c->mtd->unpoint(c->mtd, 0, c->mtd->size);
277#endif
278 if (s)
279 kfree(s);
280
281 return ret;
282}
283
284static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf,
285 uint32_t ofs, uint32_t len)
286{
287 int ret;
288 size_t retlen;
289
290 ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
291 if (ret) {
292 D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", len, ofs, ret));
293 return ret;
294 }
295 if (retlen < len) {
296 D1(printk(KERN_WARNING "Read at 0x%x gave only 0x%zx bytes\n", ofs, retlen));
297 return -EIO;
298 }
299 return 0;
300}
301
302int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
303{
304 if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
305 && (!jeb->first_node || !ref_next(jeb->first_node)) )
306 return BLK_STATE_CLEANMARKER;
307
308 /* move blocks with max 4 byte dirty space to cleanlist */
309 else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
310 c->dirty_size -= jeb->dirty_size;
311 c->wasted_size += jeb->dirty_size;
312 jeb->wasted_size += jeb->dirty_size;
313 jeb->dirty_size = 0;
314 return BLK_STATE_CLEAN;
315 } else if (jeb->used_size || jeb->unchecked_size)
316 return BLK_STATE_PARTDIRTY;
317 else
318 return BLK_STATE_ALLDIRTY;
319}
320
321#ifdef CONFIG_JFFS2_FS_XATTR
322static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
323 struct jffs2_raw_xattr *rx, uint32_t ofs,
324 struct jffs2_summary *s)
325{
326 struct jffs2_xattr_datum *xd;
327 uint32_t xid, version, totlen, crc;
328 int err;
329
330 crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
331 if (crc != je32_to_cpu(rx->node_crc)) {
332 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
333 ofs, je32_to_cpu(rx->node_crc), crc);
334 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
335 return err;
336 return 0;
337 }
338
339 xid = je32_to_cpu(rx->xid);
340 version = je32_to_cpu(rx->version);
341
342 totlen = PAD(sizeof(struct jffs2_raw_xattr)
343 + rx->name_len + 1 + je16_to_cpu(rx->value_len));
344 if (totlen != je32_to_cpu(rx->totlen)) {
345 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
346 ofs, je32_to_cpu(rx->totlen), totlen);
347 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
348 return err;
349 return 0;
350 }
351
352 xd = jffs2_setup_xattr_datum(c, xid, version);
353 if (IS_ERR(xd))
354 return PTR_ERR(xd);
355
356 if (xd->version > version) {
357 struct jffs2_raw_node_ref *raw
358 = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL);
359 raw->next_in_ino = xd->node->next_in_ino;
360 xd->node->next_in_ino = raw;
361 } else {
362 xd->version = version;
363 xd->xprefix = rx->xprefix;
364 xd->name_len = rx->name_len;
365 xd->value_len = je16_to_cpu(rx->value_len);
366 xd->data_crc = je32_to_cpu(rx->data_crc);
367
368 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd);
369 }
370
371 if (jffs2_sum_active())
372 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
373 dbg_xattr("scaning xdatum at %#08x (xid=%u, version=%u)\n",
374 ofs, xd->xid, xd->version);
375 return 0;
376}
377
378static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
379 struct jffs2_raw_xref *rr, uint32_t ofs,
380 struct jffs2_summary *s)
381{
382 struct jffs2_xattr_ref *ref;
383 uint32_t crc;
384 int err;
385
386 crc = crc32(0, rr, sizeof(*rr) - 4);
387 if (crc != je32_to_cpu(rr->node_crc)) {
388 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
389 ofs, je32_to_cpu(rr->node_crc), crc);
390 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
391 return err;
392 return 0;
393 }
394
395 if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
396 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n",
397 ofs, je32_to_cpu(rr->totlen),
398 PAD(sizeof(struct jffs2_raw_xref)));
399 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
400 return err;
401 return 0;
402 }
403
404 ref = jffs2_alloc_xattr_ref();
405 if (!ref)
406 return -ENOMEM;
407
408 /* BEFORE jffs2_build_xattr_subsystem() called,
409 * and AFTER xattr_ref is marked as a dead xref,
410 * ref->xid is used to store 32bit xid, xd is not used
411 * ref->ino is used to store 32bit inode-number, ic is not used
412 * Thoes variables are declared as union, thus using those
413 * are exclusive. In a similar way, ref->next is temporarily
414 * used to chain all xattr_ref object. It's re-chained to
415 * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
416 */
417 ref->ino = je32_to_cpu(rr->ino);
418 ref->xid = je32_to_cpu(rr->xid);
419 ref->xseqno = je32_to_cpu(rr->xseqno);
420 if (ref->xseqno > c->highest_xseqno)
421 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
422 ref->next = c->xref_temp;
423 c->xref_temp = ref;
424
425 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref);
426
427 if (jffs2_sum_active())
428 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
429 dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
430 ofs, ref->xid, ref->ino);
431 return 0;
432}
433#endif
434
435/* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
436 the flash, XIP-style */
437static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
438 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
439 struct jffs2_unknown_node *node;
440 struct jffs2_unknown_node crcnode;
441 uint32_t ofs, prevofs, max_ofs;
442 uint32_t hdr_crc, buf_ofs, buf_len;
443 int err;
444 int noise = 0;
445
446
447#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
448 int cleanmarkerfound = 0;
449#endif
450
451 ofs = jeb->offset;
452 prevofs = jeb->offset - 1;
453
454 D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs));
455
456#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
457 if (jffs2_cleanmarker_oob(c)) {
458 int ret;
459
460 if (c->mtd->block_isbad(c->mtd, jeb->offset))
461 return BLK_STATE_BADBLOCK;
462
463 ret = jffs2_check_nand_cleanmarker(c, jeb);
464 D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret));
465
466 /* Even if it's not found, we still scan to see
467 if the block is empty. We use this information
468 to decide whether to erase it or not. */
469 switch (ret) {
470 case 0: cleanmarkerfound = 1; break;
471 case 1: break;
472 default: return ret;
473 }
474 }
475#endif
476
477 if (jffs2_sum_active()) {
478 struct jffs2_sum_marker *sm;
479 void *sumptr = NULL;
480 uint32_t sumlen;
481
482 if (!buf_size) {
483 /* XIP case. Just look, point at the summary if it's there */
484 sm = (void *)buf + c->sector_size - sizeof(*sm);
485 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
486 sumptr = buf + je32_to_cpu(sm->offset);
487 sumlen = c->sector_size - je32_to_cpu(sm->offset);
488 }
489 } else {
490 /* If NAND flash, read a whole page of it. Else just the end */
491 if (c->wbuf_pagesize)
492 buf_len = c->wbuf_pagesize;
493 else
494 buf_len = sizeof(*sm);
495
496 /* Read as much as we want into the _end_ of the preallocated buffer */
497 err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len,
498 jeb->offset + c->sector_size - buf_len,
499 buf_len);
500 if (err)
501 return err;
502
503 sm = (void *)buf + buf_size - sizeof(*sm);
504 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
505 sumlen = c->sector_size - je32_to_cpu(sm->offset);
506 sumptr = buf + buf_size - sumlen;
507
508 /* Now, make sure the summary itself is available */
509 if (sumlen > buf_size) {
510 /* Need to kmalloc for this. */
511 sumptr = kmalloc(sumlen, GFP_KERNEL);
512 if (!sumptr)
513 return -ENOMEM;
514 memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
515 }
516 if (buf_len < sumlen) {
517 /* Need to read more so that the entire summary node is present */
518 err = jffs2_fill_scan_buf(c, sumptr,
519 jeb->offset + c->sector_size - sumlen,
520 sumlen - buf_len);
521 if (err)
522 return err;
523 }
524 }
525
526 }
527
528 if (sumptr) {
529 err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
530
531 if (buf_size && sumlen > buf_size)
532 kfree(sumptr);
533 /* If it returns with a real error, bail.
534 If it returns positive, that's a block classification
535 (i.e. BLK_STATE_xxx) so return that too.
536 If it returns zero, fall through to full scan. */
537 if (err)
538 return err;
539 }
540 }
541
542 buf_ofs = jeb->offset;
543
544 if (!buf_size) {
545 /* This is the XIP case -- we're reading _directly_ from the flash chip */
546 buf_len = c->sector_size;
547 } else {
548 buf_len = EMPTY_SCAN_SIZE(c->sector_size);
549 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
550 if (err)
551 return err;
552 }
553
554 /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
555 ofs = 0;
556 max_ofs = EMPTY_SCAN_SIZE(c->sector_size);
557 /* Scan only EMPTY_SCAN_SIZE of 0xFF before declaring it's empty */
558 while(ofs < max_ofs && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
559 ofs += 4;
560
561 if (ofs == max_ofs) {
562#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
563 if (jffs2_cleanmarker_oob(c)) {
564 /* scan oob, take care of cleanmarker */
565 int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
566 D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret));
567 switch (ret) {
568 case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
569 case 1: return BLK_STATE_ALLDIRTY;
570 default: return ret;
571 }
572 }
573#endif
574 D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset));
575 if (c->cleanmarker_size == 0)
576 return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */
577 else
578 return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
579 }
580 if (ofs) {
581 D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset,
582 jeb->offset + ofs));
583 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
584 return err;
585 if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
586 return err;
587 }
588
589 /* Now ofs is a complete physical flash offset as it always was... */
590 ofs += jeb->offset;
591
592 noise = 10;
593
594 dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
595
596scan_more:
597 while(ofs < jeb->offset + c->sector_size) {
598
599 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
600
601 /* Make sure there are node refs available for use */
602 err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
603 if (err)
604 return err;
605
606 cond_resched();
607
608 if (ofs & 3) {
609 printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs);
610 ofs = PAD(ofs);
611 continue;
612 }
613 if (ofs == prevofs) {
614 printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs);
615 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
616 return err;
617 ofs += 4;
618 continue;
619 }
620 prevofs = ofs;
621
622 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
623 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),
624 jeb->offset, c->sector_size, ofs, sizeof(*node)));
625 if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
626 return err;
627 break;
628 }
629
630 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
631 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
632 D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
633 sizeof(struct jffs2_unknown_node), buf_len, ofs));
634 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
635 if (err)
636 return err;
637 buf_ofs = ofs;
638 }
639
640 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
641
642 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
643 uint32_t inbuf_ofs;
644 uint32_t empty_start, scan_end;
645
646 empty_start = ofs;
647 ofs += 4;
648 scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len);
649
650 D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs));
651 more_empty:
652 inbuf_ofs = ofs - buf_ofs;
653 while (inbuf_ofs < scan_end) {
654 if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) {
655 printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n",
656 empty_start, ofs);
657 if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
658 return err;
659 goto scan_more;
660 }
661
662 inbuf_ofs+=4;
663 ofs += 4;
664 }
665 /* Ran off end. */
666 D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs));
667
668 /* If we're only checking the beginning of a block with a cleanmarker,
669 bail now */
670 if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
671 c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
672 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size)));
673 return BLK_STATE_CLEANMARKER;
674 }
675 if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */
676 scan_end = buf_len;
677 goto more_empty;
678 }
679
680 /* See how much more there is to read in this eraseblock... */
681 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
682 if (!buf_len) {
683 /* No more to read. Break out of main loop without marking
684 this range of empty space as dirty (because it's not) */
685 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n",
686 empty_start));
687 break;
688 }
689 /* point never reaches here */
690 scan_end = buf_len;
691 D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs));
692 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
693 if (err)
694 return err;
695 buf_ofs = ofs;
696 goto more_empty;
697 }
698
699 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
700 printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs);
701 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
702 return err;
703 ofs += 4;
704 continue;
705 }
706 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
707 D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs));
708 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
709 return err;
710 ofs += 4;
711 continue;
712 }
713 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
714 printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs);
715 printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n");
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_MAGIC_BITMASK) {
722 /* OK. We're out of possibilities. Whinge and move on */
723 noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
724 JFFS2_MAGIC_BITMASK, ofs,
725 je16_to_cpu(node->magic));
726 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
727 return err;
728 ofs += 4;
729 continue;
730 }
731 /* We seem to have a node of sorts. Check the CRC */
732 crcnode.magic = node->magic;
733 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
734 crcnode.totlen = node->totlen;
735 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
736
737 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
738 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",
739 ofs, je16_to_cpu(node->magic),
740 je16_to_cpu(node->nodetype),
741 je32_to_cpu(node->totlen),
742 je32_to_cpu(node->hdr_crc),
743 hdr_crc);
744 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
745 return err;
746 ofs += 4;
747 continue;
748 }
749
750 if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) {
751 /* Eep. Node goes over the end of the erase block. */
752 printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
753 ofs, je32_to_cpu(node->totlen));
754 printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
755 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
756 return err;
757 ofs += 4;
758 continue;
759 }
760
761 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
762 /* Wheee. This is an obsoleted node */
763 D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));
764 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
765 return err;
766 ofs += PAD(je32_to_cpu(node->totlen));
767 continue;
768 }
769
770 switch(je16_to_cpu(node->nodetype)) {
771 case JFFS2_NODETYPE_INODE:
772 if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
773 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
774 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
775 sizeof(struct jffs2_raw_inode), buf_len, ofs));
776 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
777 if (err)
778 return err;
779 buf_ofs = ofs;
780 node = (void *)buf;
781 }
782 err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
783 if (err) return err;
784 ofs += PAD(je32_to_cpu(node->totlen));
785 break;
786
787 case JFFS2_NODETYPE_DIRENT:
788 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
789 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
790 D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
791 je32_to_cpu(node->totlen), buf_len, ofs));
792 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
793 if (err)
794 return err;
795 buf_ofs = ofs;
796 node = (void *)buf;
797 }
798 err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
799 if (err) return err;
800 ofs += PAD(je32_to_cpu(node->totlen));
801 break;
802
803#ifdef CONFIG_JFFS2_FS_XATTR
804 case JFFS2_NODETYPE_XATTR:
805 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
806 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
807 D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)"
808 " left to end of buf. Reading 0x%x at 0x%08x\n",
809 je32_to_cpu(node->totlen), buf_len, ofs));
810 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
811 if (err)
812 return err;
813 buf_ofs = ofs;
814 node = (void *)buf;
815 }
816 err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
817 if (err)
818 return err;
819 ofs += PAD(je32_to_cpu(node->totlen));
820 break;
821 case JFFS2_NODETYPE_XREF:
822 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
823 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
824 D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)"
825 " left to end of buf. Reading 0x%x at 0x%08x\n",
826 je32_to_cpu(node->totlen), buf_len, ofs));
827 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
828 if (err)
829 return err;
830 buf_ofs = ofs;
831 node = (void *)buf;
832 }
833 err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
834 if (err)
835 return err;
836 ofs += PAD(je32_to_cpu(node->totlen));
837 break;
838#endif /* CONFIG_JFFS2_FS_XATTR */
839
840 case JFFS2_NODETYPE_CLEANMARKER:
841 D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs));
842 if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
843 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
844 ofs, je32_to_cpu(node->totlen), c->cleanmarker_size);
845 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
846 return err;
847 ofs += PAD(sizeof(struct jffs2_unknown_node));
848 } else if (jeb->first_node) {
849 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset);
850 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
851 return err;
852 ofs += PAD(sizeof(struct jffs2_unknown_node));
853 } else {
854 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
855
856 ofs += PAD(c->cleanmarker_size);
857 }
858 break;
859
860 case JFFS2_NODETYPE_PADDING:
861 if (jffs2_sum_active())
862 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
863 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
864 return err;
865 ofs += PAD(je32_to_cpu(node->totlen));
866 break;
867
868 default:
869 switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
870 case JFFS2_FEATURE_ROCOMPAT:
871 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
872 c->flags |= JFFS2_SB_FLAG_RO;
873 if (!(jffs2_is_readonly(c)))
874 return -EROFS;
875 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
876 return err;
877 ofs += PAD(je32_to_cpu(node->totlen));
878 break;
879
880 case JFFS2_FEATURE_INCOMPAT:
881 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
882 return -EINVAL;
883
884 case JFFS2_FEATURE_RWCOMPAT_DELETE:
885 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
886 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
887 return err;
888 ofs += PAD(je32_to_cpu(node->totlen));
889 break;
890
891 case JFFS2_FEATURE_RWCOMPAT_COPY: {
892 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
893
894 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
895
896 /* We can't summarise nodes we don't grok */
897 jffs2_sum_disable_collecting(s);
898 ofs += PAD(je32_to_cpu(node->totlen));
899 break;
900 }
901 }
902 }
903 }
904
905 if (jffs2_sum_active()) {
906 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
907 dbg_summary("There is not enough space for "
908 "summary information, disabling for this jeb!\n");
909 jffs2_sum_disable_collecting(s);
910 }
911 }
912
913 D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
914 jeb->offset,jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size, jeb->wasted_size));
915
916 /* mark_node_obsolete can add to wasted !! */
917 if (jeb->wasted_size) {
918 jeb->dirty_size += jeb->wasted_size;
919 c->dirty_size += jeb->wasted_size;
920 c->wasted_size -= jeb->wasted_size;
921 jeb->wasted_size = 0;
922 }
923
924 return jffs2_scan_classify_jeb(c, jeb);
925}
926
927struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
928{
929 struct jffs2_inode_cache *ic;
930
931 ic = jffs2_get_ino_cache(c, ino);
932 if (ic)
933 return ic;
934
935 if (ino > c->highest_ino)
936 c->highest_ino = ino;
937
938 ic = jffs2_alloc_inode_cache();
939 if (!ic) {
940 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n");
941 return NULL;
942 }
943 memset(ic, 0, sizeof(*ic));
944
945 ic->ino = ino;
946 ic->nodes = (void *)ic;
947 jffs2_add_ino_cache(c, ic);
948 if (ino == 1)
949 ic->pino_nlink = 1;
950 return ic;
951}
952
953static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
954 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
955{
956 struct jffs2_inode_cache *ic;
957 uint32_t crc, ino = je32_to_cpu(ri->ino);
958
959 D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs));
960
961 /* We do very little here now. Just check the ino# to which we should attribute
962 this node; we can do all the CRC checking etc. later. There's a tradeoff here --
963 we used to scan the flash once only, reading everything we want from it into
964 memory, then building all our in-core data structures and freeing the extra
965 information. Now we allow the first part of the mount to complete a lot quicker,
966 but we have to go _back_ to the flash in order to finish the CRC checking, etc.
967 Which means that the _full_ amount of time to get to proper write mode with GC
968 operational may actually be _longer_ than before. Sucks to be me. */
969
970 /* Check the node CRC in any case. */
971 crc = crc32(0, ri, sizeof(*ri)-8);
972 if (crc != je32_to_cpu(ri->node_crc)) {
973 printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on "
974 "node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
975 ofs, je32_to_cpu(ri->node_crc), crc);
976 /*
977 * We believe totlen because the CRC on the node
978 * _header_ was OK, just the node itself failed.
979 */
980 return jffs2_scan_dirty_space(c, jeb,
981 PAD(je32_to_cpu(ri->totlen)));
982 }
983
984 ic = jffs2_get_ino_cache(c, ino);
985 if (!ic) {
986 ic = jffs2_scan_make_ino_cache(c, ino);
987 if (!ic)
988 return -ENOMEM;
989 }
990
991 /* Wheee. It worked */
992 jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
993
994 D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
995 je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
996 je32_to_cpu(ri->offset),
997 je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)));
998
999 pseudo_random += je32_to_cpu(ri->version);
1000
1001 if (jffs2_sum_active()) {
1002 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
1003 }
1004
1005 return 0;
1006}
1007
1008static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
1009 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
1010{
1011 struct jffs2_full_dirent *fd;
1012 struct jffs2_inode_cache *ic;
1013 uint32_t checkedlen;
1014 uint32_t crc;
1015 int err;
1016
1017 D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs));
1018
1019 /* We don't get here unless the node is still valid, so we don't have to
1020 mask in the ACCURATE bit any more. */
1021 crc = crc32(0, rd, sizeof(*rd)-8);
1022
1023 if (crc != je32_to_cpu(rd->node_crc)) {
1024 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1025 ofs, je32_to_cpu(rd->node_crc), crc);
1026 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1027 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1028 return err;
1029 return 0;
1030 }
1031
1032 pseudo_random += je32_to_cpu(rd->version);
1033
1034 /* Should never happen. Did. (OLPC trac #4184)*/
1035 checkedlen = strnlen(rd->name, rd->nsize);
1036 if (checkedlen < rd->nsize) {
1037 printk(KERN_ERR "Dirent at %08x has zeroes in name. Truncating to %d chars\n",
1038 ofs, checkedlen);
1039 }
1040 fd = jffs2_alloc_full_dirent(checkedlen+1);
1041 if (!fd) {
1042 return -ENOMEM;
1043 }
1044 memcpy(&fd->name, rd->name, checkedlen);
1045 fd->name[checkedlen] = 0;
1046
1047 crc = crc32(0, fd->name, rd->nsize);
1048 if (crc != je32_to_cpu(rd->name_crc)) {
1049 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1050 ofs, je32_to_cpu(rd->name_crc), crc);
1051 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino)));
1052 jffs2_free_full_dirent(fd);
1053 /* FIXME: Why do we believe totlen? */
1054 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1055 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1056 return err;
1057 return 0;
1058 }
1059 ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1060 if (!ic) {
1061 jffs2_free_full_dirent(fd);
1062 return -ENOMEM;
1063 }
1064
1065 fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd),
1066 PAD(je32_to_cpu(rd->totlen)), ic);
1067
1068 fd->next = NULL;
1069 fd->version = je32_to_cpu(rd->version);
1070 fd->ino = je32_to_cpu(rd->ino);
1071 fd->nhash = full_name_hash(fd->name, checkedlen);
1072 fd->type = rd->type;
1073 jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1074
1075 if (jffs2_sum_active()) {
1076 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1077 }
1078
1079 return 0;
1080}
1081
1082static int count_list(struct list_head *l)
1083{
1084 uint32_t count = 0;
1085 struct list_head *tmp;
1086
1087 list_for_each(tmp, l) {
1088 count++;
1089 }
1090 return count;
1091}
1092
1093/* Note: This breaks if list_empty(head). I don't care. You
1094 might, if you copy this code and use it elsewhere :) */
1095static void rotate_list(struct list_head *head, uint32_t count)
1096{
1097 struct list_head *n = head->next;
1098
1099 list_del(head);
1100 while(count--) {
1101 n = n->next;
1102 }
1103 list_add(head, n);
1104}
1105
1106void jffs2_rotate_lists(struct jffs2_sb_info *c)
1107{
1108 uint32_t x;
1109 uint32_t rotateby;
1110
1111 x = count_list(&c->clean_list);
1112 if (x) {
1113 rotateby = pseudo_random % x;
1114 rotate_list((&c->clean_list), rotateby);
1115 }
1116
1117 x = count_list(&c->very_dirty_list);
1118 if (x) {
1119 rotateby = pseudo_random % x;
1120 rotate_list((&c->very_dirty_list), rotateby);
1121 }
1122
1123 x = count_list(&c->dirty_list);
1124 if (x) {
1125 rotateby = pseudo_random % x;
1126 rotate_list((&c->dirty_list), rotateby);
1127 }
1128
1129 x = count_list(&c->erasable_list);
1130 if (x) {
1131 rotateby = pseudo_random % x;
1132 rotate_list((&c->erasable_list), rotateby);
1133 }
1134
1135 if (c->nr_erasing_blocks) {
1136 rotateby = pseudo_random % c->nr_erasing_blocks;
1137 rotate_list((&c->erase_pending_list), rotateby);
1138 }
1139
1140 if (c->nr_free_blocks) {
1141 rotateby = pseudo_random % c->nr_free_blocks;
1142 rotate_list((&c->free_list), rotateby);
1143 }
1144}
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, ...) \
28do { \
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
37static uint32_t pseudo_random;
38
39static 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 */
46static 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);
48static 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
51static 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
62static 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
69static 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
91int 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_buf;
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 jffs2_sum_reset_collected(s);
279 kfree(s);
280 out_buf:
281 if (buf_size)
282 kfree(flashbuf);
283#ifndef __ECOS
284 else
285 mtd_unpoint(c->mtd, 0, c->mtd->size);
286#endif
287 return ret;
288}
289
290static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf,
291 uint32_t ofs, uint32_t len)
292{
293 int ret;
294 size_t retlen;
295
296 ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
297 if (ret) {
298 jffs2_dbg(1, "mtd->read(0x%x bytes from 0x%x) returned %d\n",
299 len, ofs, ret);
300 return ret;
301 }
302 if (retlen < len) {
303 jffs2_dbg(1, "Read at 0x%x gave only 0x%zx bytes\n",
304 ofs, retlen);
305 return -EIO;
306 }
307 return 0;
308}
309
310int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
311{
312 if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
313 && (!jeb->first_node || !ref_next(jeb->first_node)) )
314 return BLK_STATE_CLEANMARKER;
315
316 /* move blocks with max 4 byte dirty space to cleanlist */
317 else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
318 c->dirty_size -= jeb->dirty_size;
319 c->wasted_size += jeb->dirty_size;
320 jeb->wasted_size += jeb->dirty_size;
321 jeb->dirty_size = 0;
322 return BLK_STATE_CLEAN;
323 } else if (jeb->used_size || jeb->unchecked_size)
324 return BLK_STATE_PARTDIRTY;
325 else
326 return BLK_STATE_ALLDIRTY;
327}
328
329#ifdef CONFIG_JFFS2_FS_XATTR
330static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
331 struct jffs2_raw_xattr *rx, uint32_t ofs,
332 struct jffs2_summary *s)
333{
334 struct jffs2_xattr_datum *xd;
335 uint32_t xid, version, totlen, crc;
336 int err;
337
338 crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
339 if (crc != je32_to_cpu(rx->node_crc)) {
340 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
341 ofs, je32_to_cpu(rx->node_crc), crc);
342 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
343 return err;
344 return 0;
345 }
346
347 xid = je32_to_cpu(rx->xid);
348 version = je32_to_cpu(rx->version);
349
350 totlen = PAD(sizeof(struct jffs2_raw_xattr)
351 + rx->name_len + 1 + je16_to_cpu(rx->value_len));
352 if (totlen != je32_to_cpu(rx->totlen)) {
353 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
354 ofs, je32_to_cpu(rx->totlen), totlen);
355 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
356 return err;
357 return 0;
358 }
359
360 xd = jffs2_setup_xattr_datum(c, xid, version);
361 if (IS_ERR(xd))
362 return PTR_ERR(xd);
363
364 if (xd->version > version) {
365 struct jffs2_raw_node_ref *raw
366 = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL);
367 raw->next_in_ino = xd->node->next_in_ino;
368 xd->node->next_in_ino = raw;
369 } else {
370 xd->version = version;
371 xd->xprefix = rx->xprefix;
372 xd->name_len = rx->name_len;
373 xd->value_len = je16_to_cpu(rx->value_len);
374 xd->data_crc = je32_to_cpu(rx->data_crc);
375
376 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd);
377 }
378
379 if (jffs2_sum_active())
380 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
381 dbg_xattr("scanning xdatum at %#08x (xid=%u, version=%u)\n",
382 ofs, xd->xid, xd->version);
383 return 0;
384}
385
386static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
387 struct jffs2_raw_xref *rr, uint32_t ofs,
388 struct jffs2_summary *s)
389{
390 struct jffs2_xattr_ref *ref;
391 uint32_t crc;
392 int err;
393
394 crc = crc32(0, rr, sizeof(*rr) - 4);
395 if (crc != je32_to_cpu(rr->node_crc)) {
396 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
397 ofs, je32_to_cpu(rr->node_crc), crc);
398 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
399 return err;
400 return 0;
401 }
402
403 if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
404 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n",
405 ofs, je32_to_cpu(rr->totlen),
406 PAD(sizeof(struct jffs2_raw_xref)));
407 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
408 return err;
409 return 0;
410 }
411
412 ref = jffs2_alloc_xattr_ref();
413 if (!ref)
414 return -ENOMEM;
415
416 /* BEFORE jffs2_build_xattr_subsystem() called,
417 * and AFTER xattr_ref is marked as a dead xref,
418 * ref->xid is used to store 32bit xid, xd is not used
419 * ref->ino is used to store 32bit inode-number, ic is not used
420 * Thoes variables are declared as union, thus using those
421 * are exclusive. In a similar way, ref->next is temporarily
422 * used to chain all xattr_ref object. It's re-chained to
423 * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
424 */
425 ref->ino = je32_to_cpu(rr->ino);
426 ref->xid = je32_to_cpu(rr->xid);
427 ref->xseqno = je32_to_cpu(rr->xseqno);
428 if (ref->xseqno > c->highest_xseqno)
429 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
430 ref->next = c->xref_temp;
431 c->xref_temp = ref;
432
433 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref);
434
435 if (jffs2_sum_active())
436 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
437 dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
438 ofs, ref->xid, ref->ino);
439 return 0;
440}
441#endif
442
443/* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
444 the flash, XIP-style */
445static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
446 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
447 struct jffs2_unknown_node *node;
448 struct jffs2_unknown_node crcnode;
449 uint32_t ofs, prevofs, max_ofs;
450 uint32_t hdr_crc, buf_ofs, buf_len;
451 int err;
452 int noise = 0;
453
454
455#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
456 int cleanmarkerfound = 0;
457#endif
458
459 ofs = jeb->offset;
460 prevofs = jeb->offset - 1;
461
462 jffs2_dbg(1, "%s(): Scanning block at 0x%x\n", __func__, ofs);
463
464#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
465 if (jffs2_cleanmarker_oob(c)) {
466 int ret;
467
468 if (mtd_block_isbad(c->mtd, jeb->offset))
469 return BLK_STATE_BADBLOCK;
470
471 ret = jffs2_check_nand_cleanmarker(c, jeb);
472 jffs2_dbg(2, "jffs_check_nand_cleanmarker returned %d\n", ret);
473
474 /* Even if it's not found, we still scan to see
475 if the block is empty. We use this information
476 to decide whether to erase it or not. */
477 switch (ret) {
478 case 0: cleanmarkerfound = 1; break;
479 case 1: break;
480 default: return ret;
481 }
482 }
483#endif
484
485 if (jffs2_sum_active()) {
486 struct jffs2_sum_marker *sm;
487 void *sumptr = NULL;
488 uint32_t sumlen;
489
490 if (!buf_size) {
491 /* XIP case. Just look, point at the summary if it's there */
492 sm = (void *)buf + c->sector_size - sizeof(*sm);
493 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
494 sumptr = buf + je32_to_cpu(sm->offset);
495 sumlen = c->sector_size - je32_to_cpu(sm->offset);
496 }
497 } else {
498 /* If NAND flash, read a whole page of it. Else just the end */
499 if (c->wbuf_pagesize)
500 buf_len = c->wbuf_pagesize;
501 else
502 buf_len = sizeof(*sm);
503
504 /* Read as much as we want into the _end_ of the preallocated buffer */
505 err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len,
506 jeb->offset + c->sector_size - buf_len,
507 buf_len);
508 if (err)
509 return err;
510
511 sm = (void *)buf + buf_size - sizeof(*sm);
512 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
513 sumlen = c->sector_size - je32_to_cpu(sm->offset);
514 sumptr = buf + buf_size - sumlen;
515
516 /* sm->offset maybe wrong but MAGIC maybe right */
517 if (sumlen > c->sector_size)
518 goto full_scan;
519
520 /* Now, make sure the summary itself is available */
521 if (sumlen > buf_size) {
522 /* Need to kmalloc for this. */
523 sumptr = kmalloc(sumlen, GFP_KERNEL);
524 if (!sumptr)
525 return -ENOMEM;
526 memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
527 }
528 if (buf_len < sumlen) {
529 /* Need to read more so that the entire summary node is present */
530 err = jffs2_fill_scan_buf(c, sumptr,
531 jeb->offset + c->sector_size - sumlen,
532 sumlen - buf_len);
533 if (err) {
534 if (sumlen > buf_size)
535 kfree(sumptr);
536 return err;
537 }
538 }
539 }
540
541 }
542
543 if (sumptr) {
544 err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
545
546 if (buf_size && sumlen > buf_size)
547 kfree(sumptr);
548 /* If it returns with a real error, bail.
549 If it returns positive, that's a block classification
550 (i.e. BLK_STATE_xxx) so return that too.
551 If it returns zero, fall through to full scan. */
552 if (err)
553 return err;
554 }
555 }
556
557full_scan:
558 buf_ofs = jeb->offset;
559
560 if (!buf_size) {
561 /* This is the XIP case -- we're reading _directly_ from the flash chip */
562 buf_len = c->sector_size;
563 } else {
564 buf_len = EMPTY_SCAN_SIZE(c->sector_size);
565 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
566 if (err)
567 return err;
568 }
569
570 /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
571 ofs = 0;
572 max_ofs = EMPTY_SCAN_SIZE(c->sector_size);
573 /* Scan only EMPTY_SCAN_SIZE of 0xFF before declaring it's empty */
574 while(ofs < max_ofs && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
575 ofs += 4;
576
577 if (ofs == max_ofs) {
578#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
579 if (jffs2_cleanmarker_oob(c)) {
580 /* scan oob, take care of cleanmarker */
581 int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
582 jffs2_dbg(2, "jffs2_check_oob_empty returned %d\n",
583 ret);
584 switch (ret) {
585 case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
586 case 1: return BLK_STATE_ALLDIRTY;
587 default: return ret;
588 }
589 }
590#endif
591 jffs2_dbg(1, "Block at 0x%08x is empty (erased)\n",
592 jeb->offset);
593 if (c->cleanmarker_size == 0)
594 return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */
595 else
596 return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
597 }
598 if (ofs) {
599 jffs2_dbg(1, "Free space at %08x ends at %08x\n", jeb->offset,
600 jeb->offset + ofs);
601 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
602 return err;
603 if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
604 return err;
605 }
606
607 /* Now ofs is a complete physical flash offset as it always was... */
608 ofs += jeb->offset;
609
610 noise = 10;
611
612 dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
613
614scan_more:
615 while(ofs < jeb->offset + c->sector_size) {
616
617 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
618
619 /* Make sure there are node refs available for use */
620 err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
621 if (err)
622 return err;
623
624 cond_resched();
625
626 if (ofs & 3) {
627 pr_warn("Eep. ofs 0x%08x not word-aligned!\n", ofs);
628 ofs = PAD(ofs);
629 continue;
630 }
631 if (ofs == prevofs) {
632 pr_warn("ofs 0x%08x has already been seen. Skipping\n",
633 ofs);
634 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
635 return err;
636 ofs += 4;
637 continue;
638 }
639 prevofs = ofs;
640
641 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
642 jffs2_dbg(1, "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n",
643 sizeof(struct jffs2_unknown_node),
644 jeb->offset, c->sector_size, ofs,
645 sizeof(*node));
646 if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
647 return err;
648 break;
649 }
650
651 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
652 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
653 jffs2_dbg(1, "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
654 sizeof(struct jffs2_unknown_node),
655 buf_len, ofs);
656 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
657 if (err)
658 return err;
659 buf_ofs = ofs;
660 }
661
662 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
663
664 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
665 uint32_t inbuf_ofs;
666 uint32_t empty_start, scan_end;
667
668 empty_start = ofs;
669 ofs += 4;
670 scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len);
671
672 jffs2_dbg(1, "Found empty flash at 0x%08x\n", ofs);
673 more_empty:
674 inbuf_ofs = ofs - buf_ofs;
675 while (inbuf_ofs < scan_end) {
676 if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) {
677 pr_warn("Empty flash at 0x%08x ends at 0x%08x\n",
678 empty_start, ofs);
679 if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
680 return err;
681 goto scan_more;
682 }
683
684 inbuf_ofs+=4;
685 ofs += 4;
686 }
687 /* Ran off end. */
688 jffs2_dbg(1, "Empty flash to end of buffer at 0x%08x\n",
689 ofs);
690
691 /* If we're only checking the beginning of a block with a cleanmarker,
692 bail now */
693 if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
694 c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
695 jffs2_dbg(1, "%d bytes at start of block seems clean... assuming all clean\n",
696 EMPTY_SCAN_SIZE(c->sector_size));
697 return BLK_STATE_CLEANMARKER;
698 }
699 if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */
700 scan_end = buf_len;
701 goto more_empty;
702 }
703
704 /* See how much more there is to read in this eraseblock... */
705 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
706 if (!buf_len) {
707 /* No more to read. Break out of main loop without marking
708 this range of empty space as dirty (because it's not) */
709 jffs2_dbg(1, "Empty flash at %08x runs to end of block. Treating as free_space\n",
710 empty_start);
711 break;
712 }
713 /* point never reaches here */
714 scan_end = buf_len;
715 jffs2_dbg(1, "Reading another 0x%x at 0x%08x\n",
716 buf_len, ofs);
717 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
718 if (err)
719 return err;
720 buf_ofs = ofs;
721 goto more_empty;
722 }
723
724 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
725 pr_warn("Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n",
726 ofs);
727 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
728 return err;
729 ofs += 4;
730 continue;
731 }
732 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
733 jffs2_dbg(1, "Dirty bitmask at 0x%08x\n", ofs);
734 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
735 return err;
736 ofs += 4;
737 continue;
738 }
739 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
740 pr_warn("Old JFFS2 bitmask found at 0x%08x\n", ofs);
741 pr_warn("You cannot use older JFFS2 filesystems with newer kernels\n");
742 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
743 return err;
744 ofs += 4;
745 continue;
746 }
747 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
748 /* OK. We're out of possibilities. Whinge and move on */
749 noisy_printk(&noise, "%s(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
750 __func__,
751 JFFS2_MAGIC_BITMASK, ofs,
752 je16_to_cpu(node->magic));
753 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
754 return err;
755 ofs += 4;
756 continue;
757 }
758 /* We seem to have a node of sorts. Check the CRC */
759 crcnode.magic = node->magic;
760 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
761 crcnode.totlen = node->totlen;
762 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
763
764 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
765 noisy_printk(&noise, "%s(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n",
766 __func__,
767 ofs, je16_to_cpu(node->magic),
768 je16_to_cpu(node->nodetype),
769 je32_to_cpu(node->totlen),
770 je32_to_cpu(node->hdr_crc),
771 hdr_crc);
772 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
773 return err;
774 ofs += 4;
775 continue;
776 }
777
778 if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) {
779 /* Eep. Node goes over the end of the erase block. */
780 pr_warn("Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
781 ofs, je32_to_cpu(node->totlen));
782 pr_warn("Perhaps the file system was created with the wrong erase size?\n");
783 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
784 return err;
785 ofs += 4;
786 continue;
787 }
788
789 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
790 /* Wheee. This is an obsoleted node */
791 jffs2_dbg(2, "Node at 0x%08x is obsolete. Skipping\n",
792 ofs);
793 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
794 return err;
795 ofs += PAD(je32_to_cpu(node->totlen));
796 continue;
797 }
798
799 switch(je16_to_cpu(node->nodetype)) {
800 case JFFS2_NODETYPE_INODE:
801 if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
802 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
803 jffs2_dbg(1, "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
804 sizeof(struct jffs2_raw_inode),
805 buf_len, ofs);
806 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
807 if (err)
808 return err;
809 buf_ofs = ofs;
810 node = (void *)buf;
811 }
812 err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
813 if (err) return err;
814 ofs += PAD(je32_to_cpu(node->totlen));
815 break;
816
817 case JFFS2_NODETYPE_DIRENT:
818 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
819 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
820 jffs2_dbg(1, "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
821 je32_to_cpu(node->totlen), buf_len,
822 ofs);
823 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
824 if (err)
825 return err;
826 buf_ofs = ofs;
827 node = (void *)buf;
828 }
829 err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
830 if (err) return err;
831 ofs += PAD(je32_to_cpu(node->totlen));
832 break;
833
834#ifdef CONFIG_JFFS2_FS_XATTR
835 case JFFS2_NODETYPE_XATTR:
836 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
837 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
838 jffs2_dbg(1, "Fewer than %d bytes (xattr node) left to end of buf. Reading 0x%x at 0x%08x\n",
839 je32_to_cpu(node->totlen), buf_len,
840 ofs);
841 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
842 if (err)
843 return err;
844 buf_ofs = ofs;
845 node = (void *)buf;
846 }
847 err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
848 if (err)
849 return err;
850 ofs += PAD(je32_to_cpu(node->totlen));
851 break;
852 case JFFS2_NODETYPE_XREF:
853 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
854 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
855 jffs2_dbg(1, "Fewer than %d bytes (xref node) left to end of buf. Reading 0x%x at 0x%08x\n",
856 je32_to_cpu(node->totlen), buf_len,
857 ofs);
858 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
859 if (err)
860 return err;
861 buf_ofs = ofs;
862 node = (void *)buf;
863 }
864 err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
865 if (err)
866 return err;
867 ofs += PAD(je32_to_cpu(node->totlen));
868 break;
869#endif /* CONFIG_JFFS2_FS_XATTR */
870
871 case JFFS2_NODETYPE_CLEANMARKER:
872 jffs2_dbg(1, "CLEANMARKER node found at 0x%08x\n", ofs);
873 if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
874 pr_notice("CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
875 ofs, je32_to_cpu(node->totlen),
876 c->cleanmarker_size);
877 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
878 return err;
879 ofs += PAD(sizeof(struct jffs2_unknown_node));
880 } else if (jeb->first_node) {
881 pr_notice("CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n",
882 ofs, jeb->offset);
883 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
884 return err;
885 ofs += PAD(sizeof(struct jffs2_unknown_node));
886 } else {
887 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
888
889 ofs += PAD(c->cleanmarker_size);
890 }
891 break;
892
893 case JFFS2_NODETYPE_PADDING:
894 if (jffs2_sum_active())
895 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
896 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
897 return err;
898 ofs += PAD(je32_to_cpu(node->totlen));
899 break;
900
901 default:
902 switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
903 case JFFS2_FEATURE_ROCOMPAT:
904 pr_notice("Read-only compatible feature node (0x%04x) found at offset 0x%08x\n",
905 je16_to_cpu(node->nodetype), ofs);
906 c->flags |= JFFS2_SB_FLAG_RO;
907 if (!(jffs2_is_readonly(c)))
908 return -EROFS;
909 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
910 return err;
911 ofs += PAD(je32_to_cpu(node->totlen));
912 break;
913
914 case JFFS2_FEATURE_INCOMPAT:
915 pr_notice("Incompatible feature node (0x%04x) found at offset 0x%08x\n",
916 je16_to_cpu(node->nodetype), ofs);
917 return -EINVAL;
918
919 case JFFS2_FEATURE_RWCOMPAT_DELETE:
920 jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n",
921 je16_to_cpu(node->nodetype), ofs);
922 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
923 return err;
924 ofs += PAD(je32_to_cpu(node->totlen));
925 break;
926
927 case JFFS2_FEATURE_RWCOMPAT_COPY: {
928 jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n",
929 je16_to_cpu(node->nodetype), ofs);
930
931 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
932
933 /* We can't summarise nodes we don't grok */
934 jffs2_sum_disable_collecting(s);
935 ofs += PAD(je32_to_cpu(node->totlen));
936 break;
937 }
938 }
939 }
940 }
941
942 if (jffs2_sum_active()) {
943 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
944 dbg_summary("There is not enough space for "
945 "summary information, disabling for this jeb!\n");
946 jffs2_sum_disable_collecting(s);
947 }
948 }
949
950 jffs2_dbg(1, "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
951 jeb->offset, jeb->free_size, jeb->dirty_size,
952 jeb->unchecked_size, jeb->used_size, jeb->wasted_size);
953
954 /* mark_node_obsolete can add to wasted !! */
955 if (jeb->wasted_size) {
956 jeb->dirty_size += jeb->wasted_size;
957 c->dirty_size += jeb->wasted_size;
958 c->wasted_size -= jeb->wasted_size;
959 jeb->wasted_size = 0;
960 }
961
962 return jffs2_scan_classify_jeb(c, jeb);
963}
964
965struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
966{
967 struct jffs2_inode_cache *ic;
968
969 ic = jffs2_get_ino_cache(c, ino);
970 if (ic)
971 return ic;
972
973 if (ino > c->highest_ino)
974 c->highest_ino = ino;
975
976 ic = jffs2_alloc_inode_cache();
977 if (!ic) {
978 pr_notice("%s(): allocation of inode cache failed\n", __func__);
979 return NULL;
980 }
981 memset(ic, 0, sizeof(*ic));
982
983 ic->ino = ino;
984 ic->nodes = (void *)ic;
985 jffs2_add_ino_cache(c, ic);
986 if (ino == 1)
987 ic->pino_nlink = 1;
988 return ic;
989}
990
991static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
992 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
993{
994 struct jffs2_inode_cache *ic;
995 uint32_t crc, ino = je32_to_cpu(ri->ino);
996
997 jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs);
998
999 /* We do very little here now. Just check the ino# to which we should attribute
1000 this node; we can do all the CRC checking etc. later. There's a tradeoff here --
1001 we used to scan the flash once only, reading everything we want from it into
1002 memory, then building all our in-core data structures and freeing the extra
1003 information. Now we allow the first part of the mount to complete a lot quicker,
1004 but we have to go _back_ to the flash in order to finish the CRC checking, etc.
1005 Which means that the _full_ amount of time to get to proper write mode with GC
1006 operational may actually be _longer_ than before. Sucks to be me. */
1007
1008 /* Check the node CRC in any case. */
1009 crc = crc32(0, ri, sizeof(*ri)-8);
1010 if (crc != je32_to_cpu(ri->node_crc)) {
1011 pr_notice("%s(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1012 __func__, ofs, je32_to_cpu(ri->node_crc), crc);
1013 /*
1014 * We believe totlen because the CRC on the node
1015 * _header_ was OK, just the node itself failed.
1016 */
1017 return jffs2_scan_dirty_space(c, jeb,
1018 PAD(je32_to_cpu(ri->totlen)));
1019 }
1020
1021 ic = jffs2_get_ino_cache(c, ino);
1022 if (!ic) {
1023 ic = jffs2_scan_make_ino_cache(c, ino);
1024 if (!ic)
1025 return -ENOMEM;
1026 }
1027
1028 /* Wheee. It worked */
1029 jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
1030
1031 jffs2_dbg(1, "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
1032 je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
1033 je32_to_cpu(ri->offset),
1034 je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize));
1035
1036 pseudo_random += je32_to_cpu(ri->version);
1037
1038 if (jffs2_sum_active()) {
1039 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
1040 }
1041
1042 return 0;
1043}
1044
1045static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
1046 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
1047{
1048 struct jffs2_full_dirent *fd;
1049 struct jffs2_inode_cache *ic;
1050 uint32_t checkedlen;
1051 uint32_t crc;
1052 int err;
1053
1054 jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs);
1055
1056 /* We don't get here unless the node is still valid, so we don't have to
1057 mask in the ACCURATE bit any more. */
1058 crc = crc32(0, rd, sizeof(*rd)-8);
1059
1060 if (crc != je32_to_cpu(rd->node_crc)) {
1061 pr_notice("%s(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1062 __func__, ofs, je32_to_cpu(rd->node_crc), crc);
1063 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1064 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1065 return err;
1066 return 0;
1067 }
1068
1069 pseudo_random += je32_to_cpu(rd->version);
1070
1071 /* Should never happen. Did. (OLPC trac #4184)*/
1072 checkedlen = strnlen(rd->name, rd->nsize);
1073 if (checkedlen < rd->nsize) {
1074 pr_err("Dirent at %08x has zeroes in name. Truncating to %d chars\n",
1075 ofs, checkedlen);
1076 }
1077 fd = jffs2_alloc_full_dirent(checkedlen+1);
1078 if (!fd) {
1079 return -ENOMEM;
1080 }
1081 memcpy(&fd->name, rd->name, checkedlen);
1082 fd->name[checkedlen] = 0;
1083
1084 crc = crc32(0, fd->name, checkedlen);
1085 if (crc != je32_to_cpu(rd->name_crc)) {
1086 pr_notice("%s(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1087 __func__, ofs, je32_to_cpu(rd->name_crc), crc);
1088 jffs2_dbg(1, "Name for which CRC failed is (now) '%s', ino #%d\n",
1089 fd->name, je32_to_cpu(rd->ino));
1090 jffs2_free_full_dirent(fd);
1091 /* FIXME: Why do we believe totlen? */
1092 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1093 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1094 return err;
1095 return 0;
1096 }
1097 ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1098 if (!ic) {
1099 jffs2_free_full_dirent(fd);
1100 return -ENOMEM;
1101 }
1102
1103 fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd),
1104 PAD(je32_to_cpu(rd->totlen)), ic);
1105
1106 fd->next = NULL;
1107 fd->version = je32_to_cpu(rd->version);
1108 fd->ino = je32_to_cpu(rd->ino);
1109 fd->nhash = full_name_hash(NULL, fd->name, checkedlen);
1110 fd->type = rd->type;
1111 jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1112
1113 if (jffs2_sum_active()) {
1114 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1115 }
1116
1117 return 0;
1118}
1119
1120static int count_list(struct list_head *l)
1121{
1122 uint32_t count = 0;
1123 struct list_head *tmp;
1124
1125 list_for_each(tmp, l) {
1126 count++;
1127 }
1128 return count;
1129}
1130
1131/* Note: This breaks if list_empty(head). I don't care. You
1132 might, if you copy this code and use it elsewhere :) */
1133static void rotate_list(struct list_head *head, uint32_t count)
1134{
1135 struct list_head *n = head->next;
1136
1137 list_del(head);
1138 while(count--) {
1139 n = n->next;
1140 }
1141 list_add(head, n);
1142}
1143
1144void jffs2_rotate_lists(struct jffs2_sb_info *c)
1145{
1146 uint32_t x;
1147 uint32_t rotateby;
1148
1149 x = count_list(&c->clean_list);
1150 if (x) {
1151 rotateby = pseudo_random % x;
1152 rotate_list((&c->clean_list), rotateby);
1153 }
1154
1155 x = count_list(&c->very_dirty_list);
1156 if (x) {
1157 rotateby = pseudo_random % x;
1158 rotate_list((&c->very_dirty_list), rotateby);
1159 }
1160
1161 x = count_list(&c->dirty_list);
1162 if (x) {
1163 rotateby = pseudo_random % x;
1164 rotate_list((&c->dirty_list), rotateby);
1165 }
1166
1167 x = count_list(&c->erasable_list);
1168 if (x) {
1169 rotateby = pseudo_random % x;
1170 rotate_list((&c->erasable_list), rotateby);
1171 }
1172
1173 if (c->nr_erasing_blocks) {
1174 rotateby = pseudo_random % c->nr_erasing_blocks;
1175 rotate_list((&c->erase_pending_list), rotateby);
1176 }
1177
1178 if (c->nr_free_blocks) {
1179 rotateby = pseudo_random % c->nr_free_blocks;
1180 rotate_list((&c->free_list), rotateby);
1181 }
1182}