?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus
[linux-2.6/linux-mips.git] / fs / jffs2 / scan.c
blob7fb45bd4915c5c1f1cbc8ffb71bd226f5a99b24b
1 /*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright (C) 2001-2003 Red Hat, Inc.
5 *
6 * Created by David Woodhouse <dwmw2@infradead.org>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
10 * $Id: scan.c,v 1.125 2005/09/30 13:59:13 dedekind Exp $
11 *
12 */
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/slab.h>
16 #include <linux/mtd/mtd.h>
17 #include <linux/pagemap.h>
18 #include <linux/crc32.h>
19 #include <linux/compiler.h>
20 #include "nodelist.h"
21 #include "summary.h"
22 #include "debug.h"
23
24 #define DEFAULT_EMPTY_SCAN_SIZE 1024
25
26 #define noisy_printk(noise, args...) do { \
27 if (*(noise)) { \
28 printk(KERN_NOTICE args); \
29 (*(noise))--; \
30 if (!(*(noise))) { \
31 printk(KERN_NOTICE "Further such events for this erase block will not be printed\n"); \
32 } \
33 } \
34 } while(0)
35
36 static uint32_t pseudo_random;
37
38 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
39 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s);
40
41 /* These helper functions _must_ increase ofs and also do the dirty/used space accounting.
42 * Returning an error will abort the mount - bad checksums etc. should just mark the space
43 * as dirty.
44 */
45 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
46 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s);
47 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
48 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s);
49
50 static inline int min_free(struct jffs2_sb_info *c)
51 {
52 uint32_t min = 2 * sizeof(struct jffs2_raw_inode);
53 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
54 if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize)
55 return c->wbuf_pagesize;
56 #endif
57 return min;
58
59 }
60
61 static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) {
62 if (sector_size < DEFAULT_EMPTY_SCAN_SIZE)
63 return sector_size;
64 else
65 return DEFAULT_EMPTY_SCAN_SIZE;
66 }
67
68 static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
69 {
70 int ret;
71
72 if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
73 return ret;
74 if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size)))
75 return ret;
76 /* Turned wasted size into dirty, since we apparently
77 think it's recoverable now. */
78 jeb->dirty_size += jeb->wasted_size;
79 c->dirty_size += jeb->wasted_size;
80 c->wasted_size -= jeb->wasted_size;
81 jeb->wasted_size = 0;
82 if (VERYDIRTY(c, jeb->dirty_size)) {
83 list_add(&jeb->list, &c->very_dirty_list);
84 } else {
85 list_add(&jeb->list, &c->dirty_list);
86 }
87 return 0;
88 }
89
90 int jffs2_scan_medium(struct jffs2_sb_info *c)
91 {
92 int i, ret;
93 uint32_t empty_blocks = 0, bad_blocks = 0;
94 unsigned char *flashbuf = NULL;
95 uint32_t buf_size = 0;
96 struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
97 #ifndef __ECOS
98 size_t pointlen;
99
100 if (c->mtd->point) {
101 ret = c->mtd->point (c->mtd, 0, c->mtd->size, &pointlen, &flashbuf);
102 if (!ret && pointlen < c->mtd->size) {
103 /* Don't muck about if it won't let us point to the whole flash */
104 D1(printk(KERN_DEBUG "MTD point returned len too short: 0x%zx\n", pointlen));
105 c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size);
106 flashbuf = NULL;
107 }
108 if (ret)
109 D1(printk(KERN_DEBUG "MTD point failed %d\n", ret));
110 }
111 #endif
112 if (!flashbuf) {
113 /* For NAND it's quicker to read a whole eraseblock at a time,
114 apparently */
115 if (jffs2_cleanmarker_oob(c))
116 buf_size = c->sector_size;
117 else
118 buf_size = PAGE_SIZE;
119
120 /* Respect kmalloc limitations */
121 if (buf_size > 128*1024)
122 buf_size = 128*1024;
123
124 D1(printk(KERN_DEBUG "Allocating readbuf of %d bytes\n", buf_size));
125 flashbuf = kmalloc(buf_size, GFP_KERNEL);
126 if (!flashbuf)
127 return -ENOMEM;
128 }
129
130 if (jffs2_sum_active()) {
131 s = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL);
132 if (!s) {
133 kfree(flashbuf);
134 JFFS2_WARNING("Can't allocate memory for summary\n");
135 return -ENOMEM;
136 }
137 }
138
139 for (i=0; i<c->nr_blocks; i++) {
140 struct jffs2_eraseblock *jeb = &c->blocks[i];
141
142 cond_resched();
143
144 /* reset summary info for next eraseblock scan */
145 jffs2_sum_reset_collected(s);
146
147 ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
148 buf_size, s);
149
150 if (ret < 0)
151 goto out;
152
153 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
154
155 /* Now decide which list to put it on */
156 switch(ret) {
157 case BLK_STATE_ALLFF:
158 /*
159 * Empty block. Since we can't be sure it
160 * was entirely erased, we just queue it for erase
161 * again. It will be marked as such when the erase
162 * is complete. Meanwhile we still count it as empty
163 * for later checks.
164 */
165 empty_blocks++;
166 list_add(&jeb->list, &c->erase_pending_list);
167 c->nr_erasing_blocks++;
168 break;
169
170 case BLK_STATE_CLEANMARKER:
171 /* Only a CLEANMARKER node is valid */
172 if (!jeb->dirty_size) {
173 /* It's actually free */
174 list_add(&jeb->list, &c->free_list);
175 c->nr_free_blocks++;
176 } else {
177 /* Dirt */
178 D1(printk(KERN_DEBUG "Adding all-dirty block at 0x%08x to erase_pending_list\n", jeb->offset));
179 list_add(&jeb->list, &c->erase_pending_list);
180 c->nr_erasing_blocks++;
181 }
182 break;
183
184 case BLK_STATE_CLEAN:
185 /* Full (or almost full) of clean data. Clean list */
186 list_add(&jeb->list, &c->clean_list);
187 break;
188
189 case BLK_STATE_PARTDIRTY:
190 /* Some data, but not full. Dirty list. */
191 /* We want to remember the block with most free space
192 and stick it in the 'nextblock' position to start writing to it. */
193 if (jeb->free_size > min_free(c) &&
194 (!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
195 /* Better candidate for the next writes to go to */
196 if (c->nextblock) {
197 ret = file_dirty(c, c->nextblock);
198 if (ret)
199 return ret;
200 /* deleting summary information of the old nextblock */
201 jffs2_sum_reset_collected(c->summary);
202 }
203 /* update collected summary information for the current nextblock */
204 jffs2_sum_move_collected(c, s);
205 D1(printk(KERN_DEBUG "jffs2_scan_medium(): new nextblock = 0x%08x\n", jeb->offset));
206 c->nextblock = jeb;
207 } else {
208 ret = file_dirty(c, jeb);
209 if (ret)
210 return ret;
211 }
212 break;
213
214 case BLK_STATE_ALLDIRTY:
215 /* Nothing valid - not even a clean marker. Needs erasing. */
216 /* For now we just put it on the erasing list. We'll start the erases later */
217 D1(printk(KERN_NOTICE "JFFS2: Erase block at 0x%08x is not formatted. It will be erased\n", jeb->offset));
218 list_add(&jeb->list, &c->erase_pending_list);
219 c->nr_erasing_blocks++;
220 break;
221
222 case BLK_STATE_BADBLOCK:
223 D1(printk(KERN_NOTICE "JFFS2: Block at 0x%08x is bad\n", jeb->offset));
224 list_add(&jeb->list, &c->bad_list);
225 c->bad_size += c->sector_size;
226 c->free_size -= c->sector_size;
227 bad_blocks++;
228 break;
229 default:
230 printk(KERN_WARNING "jffs2_scan_medium(): unknown block state\n");
231 BUG();
232 }
233 }
234
235 /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
236 if (c->nextblock && (c->nextblock->dirty_size)) {
237 c->nextblock->wasted_size += c->nextblock->dirty_size;
238 c->wasted_size += c->nextblock->dirty_size;
239 c->dirty_size -= c->nextblock->dirty_size;
240 c->nextblock->dirty_size = 0;
241 }
242 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
243 if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) {
244 /* If we're going to start writing into a block which already
245 contains data, and the end of the data isn't page-aligned,
246 skip a little and align it. */
247
248 uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize;
249
250 D1(printk(KERN_DEBUG "jffs2_scan_medium(): Skipping %d bytes in nextblock to ensure page alignment\n",
251 skip));
252 jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
253 jffs2_scan_dirty_space(c, c->nextblock, skip);
254 }
255 #endif
256 if (c->nr_erasing_blocks) {
257 if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) {
258 printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
259 printk(KERN_NOTICE "empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",empty_blocks,bad_blocks,c->nr_blocks);
260 ret = -EIO;
261 goto out;
262 }
263 jffs2_erase_pending_trigger(c);
264 }
265 ret = 0;
266 out:
267 if (buf_size)
268 kfree(flashbuf);
269 #ifndef __ECOS
270 else
271 c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size);
272 #endif
273 if (s)
274 kfree(s);
275
276 return ret;
277 }
278
279 static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf,
280 uint32_t ofs, uint32_t len)
281 {
282 int ret;
283 size_t retlen;
284
285 ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
286 if (ret) {
287 D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", len, ofs, ret));
288 return ret;
289 }
290 if (retlen < len) {
291 D1(printk(KERN_WARNING "Read at 0x%x gave only 0x%zx bytes\n", ofs, retlen));
292 return -EIO;
293 }
294 return 0;
295 }
296
297 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
298 {
299 if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
300 && (!jeb->first_node || !ref_next(jeb->first_node)) )
301 return BLK_STATE_CLEANMARKER;
302
303 /* move blocks with max 4 byte dirty space to cleanlist */
304 else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
305 c->dirty_size -= jeb->dirty_size;
306 c->wasted_size += jeb->dirty_size;
307 jeb->wasted_size += jeb->dirty_size;
308 jeb->dirty_size = 0;
309 return BLK_STATE_CLEAN;
310 } else if (jeb->used_size || jeb->unchecked_size)
311 return BLK_STATE_PARTDIRTY;
312 else
313 return BLK_STATE_ALLDIRTY;
314 }
315
316 #ifdef CONFIG_JFFS2_FS_XATTR
317 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
318 struct jffs2_raw_xattr *rx, uint32_t ofs,
319 struct jffs2_summary *s)
320 {
321 struct jffs2_xattr_datum *xd;
322 uint32_t xid, version, totlen, crc;
323 int err;
324
325 crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
326 if (crc != je32_to_cpu(rx->node_crc)) {
327 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
328 ofs, je32_to_cpu(rx->node_crc), crc);
329 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
330 return err;
331 return 0;
332 }
333
334 xid = je32_to_cpu(rx->xid);
335 version = je32_to_cpu(rx->version);
336
337 totlen = PAD(sizeof(struct jffs2_raw_xattr)
338 + rx->name_len + 1 + je16_to_cpu(rx->value_len));
339 if (totlen != je32_to_cpu(rx->totlen)) {
340 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
341 ofs, je32_to_cpu(rx->totlen), totlen);
342 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
343 return err;
344 return 0;
345 }
346
347 xd = jffs2_setup_xattr_datum(c, xid, version);
348 if (IS_ERR(xd))
349 return PTR_ERR(xd);
350
351 if (xd->version > version) {
352 struct jffs2_raw_node_ref *raw
353 = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL);
354 raw->next_in_ino = xd->node->next_in_ino;
355 xd->node->next_in_ino = raw;
356 } else {
357 xd->version = version;
358 xd->xprefix = rx->xprefix;
359 xd->name_len = rx->name_len;
360 xd->value_len = je16_to_cpu(rx->value_len);
361 xd->data_crc = je32_to_cpu(rx->data_crc);
362
363 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd);
364 }
365
366 if (jffs2_sum_active())
367 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
368 dbg_xattr("scaning xdatum at %#08x (xid=%u, version=%u)\n",
369 ofs, xd->xid, xd->version);
370 return 0;
371 }
372
373 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
374 struct jffs2_raw_xref *rr, uint32_t ofs,
375 struct jffs2_summary *s)
376 {
377 struct jffs2_xattr_ref *ref;
378 uint32_t crc;
379 int err;
380
381 crc = crc32(0, rr, sizeof(*rr) - 4);
382 if (crc != je32_to_cpu(rr->node_crc)) {
383 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
384 ofs, je32_to_cpu(rr->node_crc), crc);
385 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
386 return err;
387 return 0;
388 }
389
390 if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
391 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n",
392 ofs, je32_to_cpu(rr->totlen),
393 PAD(sizeof(struct jffs2_raw_xref)));
394 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
395 return err;
396 return 0;
397 }
398
399 ref = jffs2_alloc_xattr_ref();
400 if (!ref)
401 return -ENOMEM;
402
403 /* BEFORE jffs2_build_xattr_subsystem() called,
404 * and AFTER xattr_ref is marked as a dead xref,
405 * ref->xid is used to store 32bit xid, xd is not used
406 * ref->ino is used to store 32bit inode-number, ic is not used
407 * Thoes variables are declared as union, thus using those
408 * are exclusive. In a similar way, ref->next is temporarily
409 * used to chain all xattr_ref object. It's re-chained to
410 * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
411 */
412 ref->ino = je32_to_cpu(rr->ino);
413 ref->xid = je32_to_cpu(rr->xid);
414 ref->xseqno = je32_to_cpu(rr->xseqno);
415 if (ref->xseqno > c->highest_xseqno)
416 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
417 ref->next = c->xref_temp;
418 c->xref_temp = ref;
419
420 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref);
421
422 if (jffs2_sum_active())
423 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
424 dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
425 ofs, ref->xid, ref->ino);
426 return 0;
427 }
428 #endif
429
430 /* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
431 the flash, XIP-style */
432 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
433 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
434 struct jffs2_unknown_node *node;
435 struct jffs2_unknown_node crcnode;
436 uint32_t ofs, prevofs;
437 uint32_t hdr_crc, buf_ofs, buf_len;
438 int err;
439 int noise = 0;
440
441
442 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
443 int cleanmarkerfound = 0;
444 #endif
445
446 ofs = jeb->offset;
447 prevofs = jeb->offset - 1;
448
449 D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs));
450
451 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
452 if (jffs2_cleanmarker_oob(c)) {
453 int ret;
454
455 if (c->mtd->block_isbad(c->mtd, jeb->offset))
456 return BLK_STATE_BADBLOCK;
457
458 ret = jffs2_check_nand_cleanmarker(c, jeb);
459 D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret));
460
461 /* Even if it's not found, we still scan to see
462 if the block is empty. We use this information
463 to decide whether to erase it or not. */
464 switch (ret) {
465 case 0: cleanmarkerfound = 1; break;
466 case 1: break;
467 default: return ret;
468 }
469 }
470 #endif
471
472 if (jffs2_sum_active()) {
473 struct jffs2_sum_marker *sm;
474 void *sumptr = NULL;
475 uint32_t sumlen;
476
477 if (!buf_size) {
478 /* XIP case. Just look, point at the summary if it's there */
479 sm = (void *)buf + c->sector_size - sizeof(*sm);
480 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
481 sumptr = buf + je32_to_cpu(sm->offset);
482 sumlen = c->sector_size - je32_to_cpu(sm->offset);
483 }
484 } else {
485 /* If NAND flash, read a whole page of it. Else just the end */
486 if (c->wbuf_pagesize)
487 buf_len = c->wbuf_pagesize;
488 else
489 buf_len = sizeof(*sm);
490
491 /* Read as much as we want into the _end_ of the preallocated buffer */
492 err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len,
493 jeb->offset + c->sector_size - buf_len,
494 buf_len);
495 if (err)
496 return err;
497
498 sm = (void *)buf + buf_size - sizeof(*sm);
499 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
500 sumlen = c->sector_size - je32_to_cpu(sm->offset);
501 sumptr = buf + buf_size - sumlen;
502
503 /* Now, make sure the summary itself is available */
504 if (sumlen > buf_size) {
505 /* Need to kmalloc for this. */
506 sumptr = kmalloc(sumlen, GFP_KERNEL);
507 if (!sumptr)
508 return -ENOMEM;
509 memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
510 }
511 if (buf_len < sumlen) {
512 /* Need to read more so that the entire summary node is present */
513 err = jffs2_fill_scan_buf(c, sumptr,
514 jeb->offset + c->sector_size - sumlen,
515 sumlen - buf_len);
516 if (err)
517 return err;
518 }
519 }
520
521 }
522
523 if (sumptr) {
524 err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
525
526 if (buf_size && sumlen > buf_size)
527 kfree(sumptr);
528 /* If it returns with a real error, bail.
529 If it returns positive, that's a block classification
530 (i.e. BLK_STATE_xxx) so return that too.
531 If it returns zero, fall through to full scan. */
532 if (err)
533 return err;
534 }
535 }
536
537 buf_ofs = jeb->offset;
538
539 if (!buf_size) {
540 /* This is the XIP case -- we're reading _directly_ from the flash chip */
541 buf_len = c->sector_size;
542 } else {
543 buf_len = EMPTY_SCAN_SIZE(c->sector_size);
544 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
545 if (err)
546 return err;
547 }
548
549 /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
550 ofs = 0;
551
552 /* Scan only 4KiB of 0xFF before declaring it's empty */
553 while(ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
554 ofs += 4;
555
556 if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) {
557 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
558 if (jffs2_cleanmarker_oob(c)) {
559 /* scan oob, take care of cleanmarker */
560 int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
561 D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret));
562 switch (ret) {
563 case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
564 case 1: return BLK_STATE_ALLDIRTY;
565 default: return ret;
566 }
567 }
568 #endif
569 D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset));
570 if (c->cleanmarker_size == 0)
571 return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */
572 else
573 return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
574 }
575 if (ofs) {
576 D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset,
577 jeb->offset + ofs));
578 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
579 return err;
580 if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
581 return err;
582 }
583
584 /* Now ofs is a complete physical flash offset as it always was... */
585 ofs += jeb->offset;
586
587 noise = 10;
588
589 dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
590
591 scan_more:
592 while(ofs < jeb->offset + c->sector_size) {
593
594 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
595
596 /* Make sure there are node refs available for use */
597 err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
598 if (err)
599 return err;
600
601 cond_resched();
602
603 if (ofs & 3) {
604 printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs);
605 ofs = PAD(ofs);
606 continue;
607 }
608 if (ofs == prevofs) {
609 printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs);
610 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
611 return err;
612 ofs += 4;
613 continue;
614 }
615 prevofs = ofs;
616
617 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
618 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),
619 jeb->offset, c->sector_size, ofs, sizeof(*node)));
620 if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
621 return err;
622 break;
623 }
624
625 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
626 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
627 D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
628 sizeof(struct jffs2_unknown_node), buf_len, ofs));
629 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
630 if (err)
631 return err;
632 buf_ofs = ofs;
633 }
634
635 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
636
637 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
638 uint32_t inbuf_ofs;
639 uint32_t empty_start;
640
641 empty_start = ofs;
642 ofs += 4;
643
644 D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs));
645 more_empty:
646 inbuf_ofs = ofs - buf_ofs;
647 while (inbuf_ofs < buf_len) {
648 if (*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff) {
649 printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n",
650 empty_start, ofs);
651 if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
652 return err;
653 goto scan_more;
654 }
655
656 inbuf_ofs+=4;
657 ofs += 4;
658 }
659 /* Ran off end. */
660 D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs));
661
662 /* If we're only checking the beginning of a block with a cleanmarker,
663 bail now */
664 if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
665 c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
666 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size)));
667 return BLK_STATE_CLEANMARKER;
668 }
669
670 /* See how much more there is to read in this eraseblock... */
671 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
672 if (!buf_len) {
673 /* No more to read. Break out of main loop without marking
674 this range of empty space as dirty (because it's not) */
675 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n",
676 empty_start));
677 break;
678 }
679 D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs));
680 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
681 if (err)
682 return err;
683 buf_ofs = ofs;
684 goto more_empty;
685 }
686
687 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
688 printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs);
689 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
690 return err;
691 ofs += 4;
692 continue;
693 }
694 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
695 D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs));
696 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
697 return err;
698 ofs += 4;
699 continue;
700 }
701 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
702 printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs);
703 printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n");
704 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
705 return err;
706 ofs += 4;
707 continue;
708 }
709 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
710 /* OK. We're out of possibilities. Whinge and move on */
711 noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
712 JFFS2_MAGIC_BITMASK, ofs,
713 je16_to_cpu(node->magic));
714 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
715 return err;
716 ofs += 4;
717 continue;
718 }
719 /* We seem to have a node of sorts. Check the CRC */
720 crcnode.magic = node->magic;
721 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
722 crcnode.totlen = node->totlen;
723 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
724
725 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
726 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",
727 ofs, je16_to_cpu(node->magic),
728 je16_to_cpu(node->nodetype),
729 je32_to_cpu(node->totlen),
730 je32_to_cpu(node->hdr_crc),
731 hdr_crc);
732 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
733 return err;
734 ofs += 4;
735 continue;
736 }
737 /* Due to poor choice of crc32 seed, an all-zero node will have a correct CRC */
738 if (!je32_to_cpu(node->hdr_crc) && !je16_to_cpu(node->nodetype) &&
739 !je16_to_cpu(node->magic) && !je32_to_cpu(node->totlen)) {
740 noisy_printk(&noise, "jffs2_scan_eraseblock(): All zero node header at 0x%08x.\n", ofs);
741 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
742 return err;
743 ofs += 4;
744 continue;
745 }
746
747 if (ofs + je32_to_cpu(node->totlen) >
748 jeb->offset + c->sector_size) {
749 /* Eep. Node goes over the end of the erase block. */
750 printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
751 ofs, je32_to_cpu(node->totlen));
752 printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
753 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
754 return err;
755 ofs += 4;
756 continue;
757 }
758
759 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
760 /* Wheee. This is an obsoleted node */
761 D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));
762 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
763 return err;
764 ofs += PAD(je32_to_cpu(node->totlen));
765 continue;
766 }
767
768 switch(je16_to_cpu(node->nodetype)) {
769 case JFFS2_NODETYPE_INODE:
770 if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
771 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
772 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
773 sizeof(struct jffs2_raw_inode), buf_len, ofs));
774 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
775 if (err)
776 return err;
777 buf_ofs = ofs;
778 node = (void *)buf;
779 }
780 err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
781 if (err) return err;
782 ofs += PAD(je32_to_cpu(node->totlen));
783 break;
784
785 case JFFS2_NODETYPE_DIRENT:
786 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
787 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
788 D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
789 je32_to_cpu(node->totlen), buf_len, ofs));
790 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
791 if (err)
792 return err;
793 buf_ofs = ofs;
794 node = (void *)buf;
795 }
796 err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
797 if (err) return err;
798 ofs += PAD(je32_to_cpu(node->totlen));
799 break;
800
801 #ifdef CONFIG_JFFS2_FS_XATTR
802 case JFFS2_NODETYPE_XATTR:
803 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
804 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
805 D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)"
806 " left to end of buf. Reading 0x%x at 0x%08x\n",
807 je32_to_cpu(node->totlen), buf_len, ofs));
808 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
809 if (err)
810 return err;
811 buf_ofs = ofs;
812 node = (void *)buf;
813 }
814 err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
815 if (err)
816 return err;
817 ofs += PAD(je32_to_cpu(node->totlen));
818 break;
819 case JFFS2_NODETYPE_XREF:
820 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
821 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
822 D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)"
823 " left to end of buf. Reading 0x%x at 0x%08x\n",
824 je32_to_cpu(node->totlen), buf_len, ofs));
825 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
826 if (err)
827 return err;
828 buf_ofs = ofs;
829 node = (void *)buf;
830 }
831 err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
832 if (err)
833 return err;
834 ofs += PAD(je32_to_cpu(node->totlen));
835 break;
836 #endif /* CONFIG_JFFS2_FS_XATTR */
837
838 case JFFS2_NODETYPE_CLEANMARKER:
839 D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs));
840 if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
841 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
842 ofs, je32_to_cpu(node->totlen), c->cleanmarker_size);
843 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
844 return err;
845 ofs += PAD(sizeof(struct jffs2_unknown_node));
846 } else if (jeb->first_node) {
847 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset);
848 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
849 return err;
850 ofs += PAD(sizeof(struct jffs2_unknown_node));
851 } else {
852 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
853
854 ofs += PAD(c->cleanmarker_size);
855 }
856 break;
857
858 case JFFS2_NODETYPE_PADDING:
859 if (jffs2_sum_active())
860 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
861 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
862 return err;
863 ofs += PAD(je32_to_cpu(node->totlen));
864 break;
865
866 default:
867 switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
868 case JFFS2_FEATURE_ROCOMPAT:
869 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
870 c->flags |= JFFS2_SB_FLAG_RO;
871 if (!(jffs2_is_readonly(c)))
872 return -EROFS;
873 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
874 return err;
875 ofs += PAD(je32_to_cpu(node->totlen));
876 break;
877
878 case JFFS2_FEATURE_INCOMPAT:
879 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
880 return -EINVAL;
881
882 case JFFS2_FEATURE_RWCOMPAT_DELETE:
883 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
884 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
885 return err;
886 ofs += PAD(je32_to_cpu(node->totlen));
887 break;
888
889 case JFFS2_FEATURE_RWCOMPAT_COPY: {
890 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
891
892 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
893
894 /* We can't summarise nodes we don't grok */
895 jffs2_sum_disable_collecting(s);
896 ofs += PAD(je32_to_cpu(node->totlen));
897 break;
898 }
899 }
900 }
901 }
902
903 if (jffs2_sum_active()) {
904 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
905 dbg_summary("There is not enough space for "
906 "summary information, disabling for this jeb!\n");
907 jffs2_sum_disable_collecting(s);
908 }
909 }
910
911 D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
912 jeb->offset,jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size, jeb->wasted_size));
913
914 /* mark_node_obsolete can add to wasted !! */
915 if (jeb->wasted_size) {
916 jeb->dirty_size += jeb->wasted_size;
917 c->dirty_size += jeb->wasted_size;
918 c->wasted_size -= jeb->wasted_size;
919 jeb->wasted_size = 0;
920 }
921
922 return jffs2_scan_classify_jeb(c, jeb);
923 }
924
925 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
926 {
927 struct jffs2_inode_cache *ic;
928
929 ic = jffs2_get_ino_cache(c, ino);
930 if (ic)
931 return ic;
932
933 if (ino > c->highest_ino)
934 c->highest_ino = ino;
935
936 ic = jffs2_alloc_inode_cache();
937 if (!ic) {
938 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n");
939 return NULL;
940 }
941 memset(ic, 0, sizeof(*ic));
942
943 ic->ino = ino;
944 ic->nodes = (void *)ic;
945 jffs2_add_ino_cache(c, ic);
946 if (ino == 1)
947 ic->nlink = 1;
948 return ic;
949 }
950
951 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
952 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
953 {
954 struct jffs2_inode_cache *ic;
955 uint32_t ino = je32_to_cpu(ri->ino);
956 int err;
957
958 D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs));
959
960 /* We do very little here now. Just check the ino# to which we should attribute
961 this node; we can do all the CRC checking etc. later. There's a tradeoff here --
962 we used to scan the flash once only, reading everything we want from it into
963 memory, then building all our in-core data structures and freeing the extra
964 information. Now we allow the first part of the mount to complete a lot quicker,
965 but we have to go _back_ to the flash in order to finish the CRC checking, etc.
966 Which means that the _full_ amount of time to get to proper write mode with GC
967 operational may actually be _longer_ than before. Sucks to be me. */
968
969 ic = jffs2_get_ino_cache(c, ino);
970 if (!ic) {
971 /* Inocache get failed. Either we read a bogus ino# or it's just genuinely the
972 first node we found for this inode. Do a CRC check to protect against the former
973 case */
974 uint32_t crc = crc32(0, ri, sizeof(*ri)-8);
975
976 if (crc != je32_to_cpu(ri->node_crc)) {
977 printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
978 ofs, je32_to_cpu(ri->node_crc), crc);
979 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
980 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(ri->totlen)))))
981 return err;
982 return 0;
983 }
984 ic = jffs2_scan_make_ino_cache(c, ino);
985 if (!ic)
986 return -ENOMEM;
987 }
988
989 /* Wheee. It worked */
990 jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
991
992 D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
993 je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
994 je32_to_cpu(ri->offset),
995 je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)));
996
997 pseudo_random += je32_to_cpu(ri->version);
998
999 if (jffs2_sum_active()) {
1000 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
1001 }
1002
1003 return 0;
1004 }
1005
1006 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
1007 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
1008 {
1009 struct jffs2_full_dirent *fd;
1010 struct jffs2_inode_cache *ic;
1011 uint32_t crc;
1012 int err;
1013
1014 D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs));
1015
1016 /* We don't get here unless the node is still valid, so we don't have to
1017 mask in the ACCURATE bit any more. */
1018 crc = crc32(0, rd, sizeof(*rd)-8);
1019
1020 if (crc != je32_to_cpu(rd->node_crc)) {
1021 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1022 ofs, je32_to_cpu(rd->node_crc), crc);
1023 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1024 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1025 return err;
1026 return 0;
1027 }
1028
1029 pseudo_random += je32_to_cpu(rd->version);
1030
1031 fd = jffs2_alloc_full_dirent(rd->nsize+1);
1032 if (!fd) {
1033 return -ENOMEM;
1034 }
1035 memcpy(&fd->name, rd->name, rd->nsize);
1036 fd->name[rd->nsize] = 0;
1037
1038 crc = crc32(0, fd->name, rd->nsize);
1039 if (crc != je32_to_cpu(rd->name_crc)) {
1040 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1041 ofs, je32_to_cpu(rd->name_crc), crc);
1042 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino)));
1043 jffs2_free_full_dirent(fd);
1044 /* FIXME: Why do we believe totlen? */
1045 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1046 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1047 return err;
1048 return 0;
1049 }
1050 ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1051 if (!ic) {
1052 jffs2_free_full_dirent(fd);
1053 return -ENOMEM;
1054 }
1055
1056 fd->raw = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rd->totlen)), ic);
1057
1058 fd->next = NULL;
1059 fd->version = je32_to_cpu(rd->version);
1060 fd->ino = je32_to_cpu(rd->ino);
1061 fd->nhash = full_name_hash(fd->name, rd->nsize);
1062 fd->type = rd->type;
1063 jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1064
1065 if (jffs2_sum_active()) {
1066 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1067 }
1068
1069 return 0;
1070 }
1071
1072 static int count_list(struct list_head *l)
1073 {
1074 uint32_t count = 0;
1075 struct list_head *tmp;
1076
1077 list_for_each(tmp, l) {
1078 count++;
1079 }
1080 return count;
1081 }
1082
1083 /* Note: This breaks if list_empty(head). I don't care. You
1084 might, if you copy this code and use it elsewhere :) */
1085 static void rotate_list(struct list_head *head, uint32_t count)
1086 {
1087 struct list_head *n = head->next;
1088
1089 list_del(head);
1090 while(count--) {
1091 n = n->next;
1092 }
1093 list_add(head, n);
1094 }
1095
1096 void jffs2_rotate_lists(struct jffs2_sb_info *c)
1097 {
1098 uint32_t x;
1099 uint32_t rotateby;
1100
1101 x = count_list(&c->clean_list);
1102 if (x) {
1103 rotateby = pseudo_random % x;
1104 rotate_list((&c->clean_list), rotateby);
1105 }
1106
1107 x = count_list(&c->very_dirty_list);
1108 if (x) {
1109 rotateby = pseudo_random % x;
1110 rotate_list((&c->very_dirty_list), rotateby);
1111 }
1112
1113 x = count_list(&c->dirty_list);
1114 if (x) {
1115 rotateby = pseudo_random % x;
1116 rotate_list((&c->dirty_list), rotateby);
1117 }
1118
1119 x = count_list(&c->erasable_list);
1120 if (x) {
1121 rotateby = pseudo_random % x;
1122 rotate_list((&c->erasable_list), rotateby);
1123 }
1124
1125 if (c->nr_erasing_blocks) {
1126 rotateby = pseudo_random % c->nr_erasing_blocks;
1127 rotate_list((&c->erase_pending_list), rotateby);
1128 }
1129
1130 if (c->nr_free_blocks) {
1131 rotateby = pseudo_random % c->nr_free_blocks;
1132 rotate_list((&c->free_list), rotateby);
1133 }
1134 }
Mirror of the linux-mips.org kernel tree