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Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / jffs2 / scan.c
blobb632dddcb482821122918bd1673391ff34d51e4c
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
35 static uint32_t pseudo_random;
36
37 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
38 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s);
39
40 /* These helper functions _must_ increase ofs and also do the dirty/used space accounting.
41 * Returning an error will abort the mount - bad checksums etc. should just mark the space
42 * as dirty.
43 */
44 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
45 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s);
46 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
47 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s);
48
49 static inline int min_free(struct jffs2_sb_info *c)
50 {
51 uint32_t min = 2 * sizeof(struct jffs2_raw_inode);
52 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
53 if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize)
54 return c->wbuf_pagesize;
55 #endif
56 return min;
57
58 }
59
60 static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) {
61 if (sector_size < DEFAULT_EMPTY_SCAN_SIZE)
62 return sector_size;
63 else
64 return DEFAULT_EMPTY_SCAN_SIZE;
65 }
66
67 static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
68 {
69 int ret;
70
71 if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
72 return ret;
73 if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size)))
74 return ret;
75 /* Turned wasted size into dirty, since we apparently
76 think it's recoverable now. */
77 jeb->dirty_size += jeb->wasted_size;
78 c->dirty_size += jeb->wasted_size;
79 c->wasted_size -= jeb->wasted_size;
80 jeb->wasted_size = 0;
81 if (VERYDIRTY(c, jeb->dirty_size)) {
82 list_add(&jeb->list, &c->very_dirty_list);
83 } else {
84 list_add(&jeb->list, &c->dirty_list);
85 }
86 return 0;
87 }
88
89 int jffs2_scan_medium(struct jffs2_sb_info *c)
90 {
91 int i, ret;
92 uint32_t empty_blocks = 0, bad_blocks = 0;
93 unsigned char *flashbuf = NULL;
94 uint32_t buf_size = 0;
95 struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
96 #ifndef __ECOS
97 size_t pointlen;
98
99 if (c->mtd->point) {
100 ret = c->mtd->point(c->mtd, 0, c->mtd->size, &pointlen,
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 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 JFFS2_WARNING("Can't allocate memory for summary\n");
134 ret = -ENOMEM;
135 goto out;
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 goto out;
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 goto out;
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 spin_lock(&c->erase_completion_lock);
264 jffs2_garbage_collect_trigger(c);
265 spin_unlock(&c->erase_completion_lock);
266 }
267 ret = 0;
268 out:
269 if (buf_size)
270 kfree(flashbuf);
271 #ifndef __ECOS
272 else
273 c->mtd->unpoint(c->mtd, 0, c->mtd->size);
274 #endif
275 if (s)
276 kfree(s);
277
278 return ret;
279 }
280
281 static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf,
282 uint32_t ofs, uint32_t len)
283 {
284 int ret;
285 size_t retlen;
286
287 ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
288 if (ret) {
289 D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", len, ofs, ret));
290 return ret;
291 }
292 if (retlen < len) {
293 D1(printk(KERN_WARNING "Read at 0x%x gave only 0x%zx bytes\n", ofs, retlen));
294 return -EIO;
295 }
296 return 0;
297 }
298
299 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
300 {
301 if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
302 && (!jeb->first_node || !ref_next(jeb->first_node)) )
303 return BLK_STATE_CLEANMARKER;
304
305 /* move blocks with max 4 byte dirty space to cleanlist */
306 else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
307 c->dirty_size -= jeb->dirty_size;
308 c->wasted_size += jeb->dirty_size;
309 jeb->wasted_size += jeb->dirty_size;
310 jeb->dirty_size = 0;
311 return BLK_STATE_CLEAN;
312 } else if (jeb->used_size || jeb->unchecked_size)
313 return BLK_STATE_PARTDIRTY;
314 else
315 return BLK_STATE_ALLDIRTY;
316 }
317
318 #ifdef CONFIG_JFFS2_FS_XATTR
319 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
320 struct jffs2_raw_xattr *rx, uint32_t ofs,
321 struct jffs2_summary *s)
322 {
323 struct jffs2_xattr_datum *xd;
324 uint32_t xid, version, totlen, crc;
325 int err;
326
327 crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
328 if (crc != je32_to_cpu(rx->node_crc)) {
329 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
330 ofs, je32_to_cpu(rx->node_crc), crc);
331 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
332 return err;
333 return 0;
334 }
335
336 xid = je32_to_cpu(rx->xid);
337 version = je32_to_cpu(rx->version);
338
339 totlen = PAD(sizeof(struct jffs2_raw_xattr)
340 + rx->name_len + 1 + je16_to_cpu(rx->value_len));
341 if (totlen != je32_to_cpu(rx->totlen)) {
342 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
343 ofs, je32_to_cpu(rx->totlen), totlen);
344 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
345 return err;
346 return 0;
347 }
348
349 xd = jffs2_setup_xattr_datum(c, xid, version);
350 if (IS_ERR(xd))
351 return PTR_ERR(xd);
352
353 if (xd->version > version) {
354 struct jffs2_raw_node_ref *raw
355 = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL);
356 raw->next_in_ino = xd->node->next_in_ino;
357 xd->node->next_in_ino = raw;
358 } else {
359 xd->version = version;
360 xd->xprefix = rx->xprefix;
361 xd->name_len = rx->name_len;
362 xd->value_len = je16_to_cpu(rx->value_len);
363 xd->data_crc = je32_to_cpu(rx->data_crc);
364
365 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd);
366 }
367
368 if (jffs2_sum_active())
369 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
370 dbg_xattr("scaning xdatum at %#08x (xid=%u, version=%u)\n",
371 ofs, xd->xid, xd->version);
372 return 0;
373 }
374
375 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
376 struct jffs2_raw_xref *rr, uint32_t ofs,
377 struct jffs2_summary *s)
378 {
379 struct jffs2_xattr_ref *ref;
380 uint32_t crc;
381 int err;
382
383 crc = crc32(0, rr, sizeof(*rr) - 4);
384 if (crc != je32_to_cpu(rr->node_crc)) {
385 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
386 ofs, je32_to_cpu(rr->node_crc), crc);
387 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
388 return err;
389 return 0;
390 }
391
392 if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
393 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n",
394 ofs, je32_to_cpu(rr->totlen),
395 PAD(sizeof(struct jffs2_raw_xref)));
396 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
397 return err;
398 return 0;
399 }
400
401 ref = jffs2_alloc_xattr_ref();
402 if (!ref)
403 return -ENOMEM;
404
405 /* BEFORE jffs2_build_xattr_subsystem() called,
406 * and AFTER xattr_ref is marked as a dead xref,
407 * ref->xid is used to store 32bit xid, xd is not used
408 * ref->ino is used to store 32bit inode-number, ic is not used
409 * Thoes variables are declared as union, thus using those
410 * are exclusive. In a similar way, ref->next is temporarily
411 * used to chain all xattr_ref object. It's re-chained to
412 * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
413 */
414 ref->ino = je32_to_cpu(rr->ino);
415 ref->xid = je32_to_cpu(rr->xid);
416 ref->xseqno = je32_to_cpu(rr->xseqno);
417 if (ref->xseqno > c->highest_xseqno)
418 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
419 ref->next = c->xref_temp;
420 c->xref_temp = ref;
421
422 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref);
423
424 if (jffs2_sum_active())
425 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
426 dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
427 ofs, ref->xid, ref->ino);
428 return 0;
429 }
430 #endif
431
432 /* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
433 the flash, XIP-style */
434 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
435 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
436 struct jffs2_unknown_node *node;
437 struct jffs2_unknown_node crcnode;
438 uint32_t ofs, prevofs, max_ofs;
439 uint32_t hdr_crc, buf_ofs, buf_len;
440 int err;
441 int noise = 0;
442
443
444 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
445 int cleanmarkerfound = 0;
446 #endif
447
448 ofs = jeb->offset;
449 prevofs = jeb->offset - 1;
450
451 D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs));
452
453 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
454 if (jffs2_cleanmarker_oob(c)) {
455 int ret;
456
457 if (c->mtd->block_isbad(c->mtd, jeb->offset))
458 return BLK_STATE_BADBLOCK;
459
460 ret = jffs2_check_nand_cleanmarker(c, jeb);
461 D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret));
462
463 /* Even if it's not found, we still scan to see
464 if the block is empty. We use this information
465 to decide whether to erase it or not. */
466 switch (ret) {
467 case 0: cleanmarkerfound = 1; break;
468 case 1: break;
469 default: return ret;
470 }
471 }
472 #endif
473
474 if (jffs2_sum_active()) {
475 struct jffs2_sum_marker *sm;
476 void *sumptr = NULL;
477 uint32_t sumlen;
478
479 if (!buf_size) {
480 /* XIP case. Just look, point at the summary if it's there */
481 sm = (void *)buf + c->sector_size - sizeof(*sm);
482 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
483 sumptr = buf + je32_to_cpu(sm->offset);
484 sumlen = c->sector_size - je32_to_cpu(sm->offset);
485 }
486 } else {
487 /* If NAND flash, read a whole page of it. Else just the end */
488 if (c->wbuf_pagesize)
489 buf_len = c->wbuf_pagesize;
490 else
491 buf_len = sizeof(*sm);
492
493 /* Read as much as we want into the _end_ of the preallocated buffer */
494 err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len,
495 jeb->offset + c->sector_size - buf_len,
496 buf_len);
497 if (err)
498 return err;
499
500 sm = (void *)buf + buf_size - sizeof(*sm);
501 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
502 sumlen = c->sector_size - je32_to_cpu(sm->offset);
503 sumptr = buf + buf_size - sumlen;
504
505 /* Now, make sure the summary itself is available */
506 if (sumlen > buf_size) {
507 /* Need to kmalloc for this. */
508 sumptr = kmalloc(sumlen, GFP_KERNEL);
509 if (!sumptr)
510 return -ENOMEM;
511 memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
512 }
513 if (buf_len < sumlen) {
514 /* Need to read more so that the entire summary node is present */
515 err = jffs2_fill_scan_buf(c, sumptr,
516 jeb->offset + c->sector_size - sumlen,
517 sumlen - buf_len);
518 if (err)
519 return err;
520 }
521 }
522
523 }
524
525 if (sumptr) {
526 err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
527
528 if (buf_size && sumlen > buf_size)
529 kfree(sumptr);
530 /* If it returns with a real error, bail.
531 If it returns positive, that's a block classification
532 (i.e. BLK_STATE_xxx) so return that too.
533 If it returns zero, fall through to full scan. */
534 if (err)
535 return err;
536 }
537 }
538
539 buf_ofs = jeb->offset;
540
541 if (!buf_size) {
542 /* This is the XIP case -- we're reading _directly_ from the flash chip */
543 buf_len = c->sector_size;
544 } else {
545 buf_len = EMPTY_SCAN_SIZE(c->sector_size);
546 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
547 if (err)
548 return err;
549 }
550
551 /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
552 ofs = 0;
553 max_ofs = EMPTY_SCAN_SIZE(c->sector_size);
554 /* Scan only EMPTY_SCAN_SIZE of 0xFF before declaring it's empty */
555 while(ofs < max_ofs && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
556 ofs += 4;
557
558 if (ofs == max_ofs) {
559 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
560 if (jffs2_cleanmarker_oob(c)) {
561 /* scan oob, take care of cleanmarker */
562 int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
563 D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret));
564 switch (ret) {
565 case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
566 case 1: return BLK_STATE_ALLDIRTY;
567 default: return ret;
568 }
569 }
570 #endif
571 D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset));
572 if (c->cleanmarker_size == 0)
573 return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */
574 else
575 return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
576 }
577 if (ofs) {
578 D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset,
579 jeb->offset + ofs));
580 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
581 return err;
582 if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
583 return err;
584 }
585
586 /* Now ofs is a complete physical flash offset as it always was... */
587 ofs += jeb->offset;
588
589 noise = 10;
590
591 dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
592
593 scan_more:
594 while(ofs < jeb->offset + c->sector_size) {
595
596 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
597
598 /* Make sure there are node refs available for use */
599 err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
600 if (err)
601 return err;
602
603 cond_resched();
604
605 if (ofs & 3) {
606 printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs);
607 ofs = PAD(ofs);
608 continue;
609 }
610 if (ofs == prevofs) {
611 printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs);
612 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
613 return err;
614 ofs += 4;
615 continue;
616 }
617 prevofs = ofs;
618
619 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
620 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),
621 jeb->offset, c->sector_size, ofs, sizeof(*node)));
622 if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
623 return err;
624 break;
625 }
626
627 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
628 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
629 D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
630 sizeof(struct jffs2_unknown_node), buf_len, ofs));
631 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
632 if (err)
633 return err;
634 buf_ofs = ofs;
635 }
636
637 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
638
639 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
640 uint32_t inbuf_ofs;
641 uint32_t empty_start, scan_end;
642
643 empty_start = ofs;
644 ofs += 4;
645 scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len);
646
647 D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs));
648 more_empty:
649 inbuf_ofs = ofs - buf_ofs;
650 while (inbuf_ofs < scan_end) {
651 if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) {
652 printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n",
653 empty_start, ofs);
654 if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
655 return err;
656 goto scan_more;
657 }
658
659 inbuf_ofs+=4;
660 ofs += 4;
661 }
662 /* Ran off end. */
663 D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs));
664
665 /* If we're only checking the beginning of a block with a cleanmarker,
666 bail now */
667 if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
668 c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
669 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size)));
670 return BLK_STATE_CLEANMARKER;
671 }
672 if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */
673 scan_end = buf_len;
674 goto more_empty;
675 }
676
677 /* See how much more there is to read in this eraseblock... */
678 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
679 if (!buf_len) {
680 /* No more to read. Break out of main loop without marking
681 this range of empty space as dirty (because it's not) */
682 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n",
683 empty_start));
684 break;
685 }
686 /* point never reaches here */
687 scan_end = buf_len;
688 D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs));
689 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
690 if (err)
691 return err;
692 buf_ofs = ofs;
693 goto more_empty;
694 }
695
696 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
697 printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs);
698 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
699 return err;
700 ofs += 4;
701 continue;
702 }
703 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
704 D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs));
705 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
706 return err;
707 ofs += 4;
708 continue;
709 }
710 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
711 printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs);
712 printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n");
713 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
714 return err;
715 ofs += 4;
716 continue;
717 }
718 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
719 /* OK. We're out of possibilities. Whinge and move on */
720 noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
721 JFFS2_MAGIC_BITMASK, ofs,
722 je16_to_cpu(node->magic));
723 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
724 return err;
725 ofs += 4;
726 continue;
727 }
728 /* We seem to have a node of sorts. Check the CRC */
729 crcnode.magic = node->magic;
730 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
731 crcnode.totlen = node->totlen;
732 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
733
734 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
735 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",
736 ofs, je16_to_cpu(node->magic),
737 je16_to_cpu(node->nodetype),
738 je32_to_cpu(node->totlen),
739 je32_to_cpu(node->hdr_crc),
740 hdr_crc);
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) > jeb->offset + c->sector_size) {
748 /* Eep. Node goes over the end of the erase block. */
749 printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
750 ofs, je32_to_cpu(node->totlen));
751 printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
752 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
753 return err;
754 ofs += 4;
755 continue;
756 }
757
758 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
759 /* Wheee. This is an obsoleted node */
760 D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));
761 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
762 return err;
763 ofs += PAD(je32_to_cpu(node->totlen));
764 continue;
765 }
766
767 switch(je16_to_cpu(node->nodetype)) {
768 case JFFS2_NODETYPE_INODE:
769 if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
770 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
771 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
772 sizeof(struct jffs2_raw_inode), buf_len, ofs));
773 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
774 if (err)
775 return err;
776 buf_ofs = ofs;
777 node = (void *)buf;
778 }
779 err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
780 if (err) return err;
781 ofs += PAD(je32_to_cpu(node->totlen));
782 break;
783
784 case JFFS2_NODETYPE_DIRENT:
785 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
786 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
787 D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
788 je32_to_cpu(node->totlen), buf_len, ofs));
789 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
790 if (err)
791 return err;
792 buf_ofs = ofs;
793 node = (void *)buf;
794 }
795 err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
796 if (err) return err;
797 ofs += PAD(je32_to_cpu(node->totlen));
798 break;
799
800 #ifdef CONFIG_JFFS2_FS_XATTR
801 case JFFS2_NODETYPE_XATTR:
802 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
803 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
804 D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)"
805 " left to end of buf. Reading 0x%x at 0x%08x\n",
806 je32_to_cpu(node->totlen), buf_len, ofs));
807 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
808 if (err)
809 return err;
810 buf_ofs = ofs;
811 node = (void *)buf;
812 }
813 err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
814 if (err)
815 return err;
816 ofs += PAD(je32_to_cpu(node->totlen));
817 break;
818 case JFFS2_NODETYPE_XREF:
819 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
820 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
821 D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)"
822 " left to end of buf. Reading 0x%x at 0x%08x\n",
823 je32_to_cpu(node->totlen), buf_len, ofs));
824 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
825 if (err)
826 return err;
827 buf_ofs = ofs;
828 node = (void *)buf;
829 }
830 err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
831 if (err)
832 return err;
833 ofs += PAD(je32_to_cpu(node->totlen));
834 break;
835 #endif /* CONFIG_JFFS2_FS_XATTR */
836
837 case JFFS2_NODETYPE_CLEANMARKER:
838 D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs));
839 if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
840 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
841 ofs, je32_to_cpu(node->totlen), c->cleanmarker_size);
842 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
843 return err;
844 ofs += PAD(sizeof(struct jffs2_unknown_node));
845 } else if (jeb->first_node) {
846 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset);
847 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
848 return err;
849 ofs += PAD(sizeof(struct jffs2_unknown_node));
850 } else {
851 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
852
853 ofs += PAD(c->cleanmarker_size);
854 }
855 break;
856
857 case JFFS2_NODETYPE_PADDING:
858 if (jffs2_sum_active())
859 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
860 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
861 return err;
862 ofs += PAD(je32_to_cpu(node->totlen));
863 break;
864
865 default:
866 switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
867 case JFFS2_FEATURE_ROCOMPAT:
868 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
869 c->flags |= JFFS2_SB_FLAG_RO;
870 if (!(jffs2_is_readonly(c)))
871 return -EROFS;
872 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
873 return err;
874 ofs += PAD(je32_to_cpu(node->totlen));
875 break;
876
877 case JFFS2_FEATURE_INCOMPAT:
878 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
879 return -EINVAL;
880
881 case JFFS2_FEATURE_RWCOMPAT_DELETE:
882 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
883 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
884 return err;
885 ofs += PAD(je32_to_cpu(node->totlen));
886 break;
887
888 case JFFS2_FEATURE_RWCOMPAT_COPY: {
889 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
890
891 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
892
893 /* We can't summarise nodes we don't grok */
894 jffs2_sum_disable_collecting(s);
895 ofs += PAD(je32_to_cpu(node->totlen));
896 break;
897 }
898 }
899 }
900 }
901
902 if (jffs2_sum_active()) {
903 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
904 dbg_summary("There is not enough space for "
905 "summary information, disabling for this jeb!\n");
906 jffs2_sum_disable_collecting(s);
907 }
908 }
909
910 D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
911 jeb->offset,jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size, jeb->wasted_size));
912
913 /* mark_node_obsolete can add to wasted !! */
914 if (jeb->wasted_size) {
915 jeb->dirty_size += jeb->wasted_size;
916 c->dirty_size += jeb->wasted_size;
917 c->wasted_size -= jeb->wasted_size;
918 jeb->wasted_size = 0;
919 }
920
921 return jffs2_scan_classify_jeb(c, jeb);
922 }
923
924 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
925 {
926 struct jffs2_inode_cache *ic;
927
928 ic = jffs2_get_ino_cache(c, ino);
929 if (ic)
930 return ic;
931
932 if (ino > c->highest_ino)
933 c->highest_ino = ino;
934
935 ic = jffs2_alloc_inode_cache();
936 if (!ic) {
937 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n");
938 return NULL;
939 }
940 memset(ic, 0, sizeof(*ic));
941
942 ic->ino = ino;
943 ic->nodes = (void *)ic;
944 jffs2_add_ino_cache(c, ic);
945 if (ino == 1)
946 ic->pino_nlink = 1;
947 return ic;
948 }
949
950 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
951 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
952 {
953 struct jffs2_inode_cache *ic;
954 uint32_t crc, ino = je32_to_cpu(ri->ino);
955
956 D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs));
957
958 /* We do very little here now. Just check the ino# to which we should attribute
959 this node; we can do all the CRC checking etc. later. There's a tradeoff here --
960 we used to scan the flash once only, reading everything we want from it into
961 memory, then building all our in-core data structures and freeing the extra
962 information. Now we allow the first part of the mount to complete a lot quicker,
963 but we have to go _back_ to the flash in order to finish the CRC checking, etc.
964 Which means that the _full_ amount of time to get to proper write mode with GC
965 operational may actually be _longer_ than before. Sucks to be me. */
966
967 /* Check the node CRC in any case. */
968 crc = crc32(0, ri, sizeof(*ri)-8);
969 if (crc != je32_to_cpu(ri->node_crc)) {
970 printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on "
971 "node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
972 ofs, je32_to_cpu(ri->node_crc), crc);
973 /*
974 * We believe totlen because the CRC on the node
975 * _header_ was OK, just the node itself failed.
976 */
977 return jffs2_scan_dirty_space(c, jeb,
978 PAD(je32_to_cpu(ri->totlen)));
979 }
980
981 ic = jffs2_get_ino_cache(c, ino);
982 if (!ic) {
983 ic = jffs2_scan_make_ino_cache(c, ino);
984 if (!ic)
985 return -ENOMEM;
986 }
987
988 /* Wheee. It worked */
989 jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
990
991 D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
992 je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
993 je32_to_cpu(ri->offset),
994 je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)));
995
996 pseudo_random += je32_to_cpu(ri->version);
997
998 if (jffs2_sum_active()) {
999 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
1000 }
1001
1002 return 0;
1003 }
1004
1005 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
1006 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
1007 {
1008 struct jffs2_full_dirent *fd;
1009 struct jffs2_inode_cache *ic;
1010 uint32_t checkedlen;
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 /* Should never happen. Did. (OLPC trac #4184)*/
1032 checkedlen = strnlen(rd->name, rd->nsize);
1033 if (checkedlen < rd->nsize) {
1034 printk(KERN_ERR "Dirent at %08x has zeroes in name. Truncating to %d chars\n",
1035 ofs, checkedlen);
1036 }
1037 fd = jffs2_alloc_full_dirent(checkedlen+1);
1038 if (!fd) {
1039 return -ENOMEM;
1040 }
1041 memcpy(&fd->name, rd->name, checkedlen);
1042 fd->name[checkedlen] = 0;
1043
1044 crc = crc32(0, fd->name, rd->nsize);
1045 if (crc != je32_to_cpu(rd->name_crc)) {
1046 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1047 ofs, je32_to_cpu(rd->name_crc), crc);
1048 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino)));
1049 jffs2_free_full_dirent(fd);
1050 /* FIXME: Why do we believe totlen? */
1051 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1052 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1053 return err;
1054 return 0;
1055 }
1056 ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1057 if (!ic) {
1058 jffs2_free_full_dirent(fd);
1059 return -ENOMEM;
1060 }
1061
1062 fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd),
1063 PAD(je32_to_cpu(rd->totlen)), ic);
1064
1065 fd->next = NULL;
1066 fd->version = je32_to_cpu(rd->version);
1067 fd->ino = je32_to_cpu(rd->ino);
1068 fd->nhash = full_name_hash(fd->name, checkedlen);
1069 fd->type = rd->type;
1070 jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1071
1072 if (jffs2_sum_active()) {
1073 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1074 }
1075
1076 return 0;
1077 }
1078
1079 static int count_list(struct list_head *l)
1080 {
1081 uint32_t count = 0;
1082 struct list_head *tmp;
1083
1084 list_for_each(tmp, l) {
1085 count++;
1086 }
1087 return count;
1088 }
1089
1090 /* Note: This breaks if list_empty(head). I don't care. You
1091 might, if you copy this code and use it elsewhere :) */
1092 static void rotate_list(struct list_head *head, uint32_t count)
1093 {
1094 struct list_head *n = head->next;
1095
1096 list_del(head);
1097 while(count--) {
1098 n = n->next;
1099 }
1100 list_add(head, n);
1101 }
1102
1103 void jffs2_rotate_lists(struct jffs2_sb_info *c)
1104 {
1105 uint32_t x;
1106 uint32_t rotateby;
1107
1108 x = count_list(&c->clean_list);
1109 if (x) {
1110 rotateby = pseudo_random % x;
1111 rotate_list((&c->clean_list), rotateby);
1112 }
1113
1114 x = count_list(&c->very_dirty_list);
1115 if (x) {
1116 rotateby = pseudo_random % x;
1117 rotate_list((&c->very_dirty_list), rotateby);
1118 }
1119
1120 x = count_list(&c->dirty_list);
1121 if (x) {
1122 rotateby = pseudo_random % x;
1123 rotate_list((&c->dirty_list), rotateby);
1124 }
1125
1126 x = count_list(&c->erasable_list);
1127 if (x) {
1128 rotateby = pseudo_random % x;
1129 rotate_list((&c->erasable_list), rotateby);
1130 }
1131
1132 if (c->nr_erasing_blocks) {
1133 rotateby = pseudo_random % c->nr_erasing_blocks;
1134 rotate_list((&c->erase_pending_list), rotateby);
1135 }
1136
1137 if (c->nr_free_blocks) {
1138 rotateby = pseudo_random % c->nr_free_blocks;
1139 rotate_list((&c->free_list), rotateby);
1140 }
1141 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree