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[JFFS2] Introduce jffs2_scan_dirty_space() function.
[linux-2.6/sactl.git] / fs / jffs2 / scan.c
blobb3fc9fd5b03db5a00cb118624f08dde16c6255a0
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 int jffs2_scan_medium(struct jffs2_sb_info *c)
69 {
70 int i, ret;
71 uint32_t empty_blocks = 0, bad_blocks = 0;
72 unsigned char *flashbuf = NULL;
73 uint32_t buf_size = 0;
74 struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
75 #ifndef __ECOS
76 size_t pointlen;
77
78 if (c->mtd->point) {
79 ret = c->mtd->point (c->mtd, 0, c->mtd->size, &pointlen, &flashbuf);
80 if (!ret && pointlen < c->mtd->size) {
81 /* Don't muck about if it won't let us point to the whole flash */
82 D1(printk(KERN_DEBUG "MTD point returned len too short: 0x%zx\n", pointlen));
83 c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size);
84 flashbuf = NULL;
85 }
86 if (ret)
87 D1(printk(KERN_DEBUG "MTD point failed %d\n", ret));
88 }
89 #endif
90 if (!flashbuf) {
91 /* For NAND it's quicker to read a whole eraseblock at a time,
92 apparently */
93 if (jffs2_cleanmarker_oob(c))
94 buf_size = c->sector_size;
95 else
96 buf_size = PAGE_SIZE;
97
98 /* Respect kmalloc limitations */
99 if (buf_size > 128*1024)
100 buf_size = 128*1024;
101
102 D1(printk(KERN_DEBUG "Allocating readbuf of %d bytes\n", buf_size));
103 flashbuf = kmalloc(buf_size, GFP_KERNEL);
104 if (!flashbuf)
105 return -ENOMEM;
106 }
107
108 if (jffs2_sum_active()) {
109 s = kmalloc(sizeof(struct jffs2_summary), GFP_KERNEL);
110 if (!s) {
111 JFFS2_WARNING("Can't allocate memory for summary\n");
112 return -ENOMEM;
113 }
114 memset(s, 0, sizeof(struct jffs2_summary));
115 }
116
117 for (i=0; i<c->nr_blocks; i++) {
118 struct jffs2_eraseblock *jeb = &c->blocks[i];
119
120 /* reset summary info for next eraseblock scan */
121 jffs2_sum_reset_collected(s);
122
123 ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
124 buf_size, s);
125
126 if (ret < 0)
127 goto out;
128
129 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
130
131 /* Now decide which list to put it on */
132 switch(ret) {
133 case BLK_STATE_ALLFF:
134 /*
135 * Empty block. Since we can't be sure it
136 * was entirely erased, we just queue it for erase
137 * again. It will be marked as such when the erase
138 * is complete. Meanwhile we still count it as empty
139 * for later checks.
140 */
141 empty_blocks++;
142 list_add(&jeb->list, &c->erase_pending_list);
143 c->nr_erasing_blocks++;
144 break;
145
146 case BLK_STATE_CLEANMARKER:
147 /* Only a CLEANMARKER node is valid */
148 if (!jeb->dirty_size) {
149 /* It's actually free */
150 list_add(&jeb->list, &c->free_list);
151 c->nr_free_blocks++;
152 } else {
153 /* Dirt */
154 D1(printk(KERN_DEBUG "Adding all-dirty block at 0x%08x to erase_pending_list\n", jeb->offset));
155 list_add(&jeb->list, &c->erase_pending_list);
156 c->nr_erasing_blocks++;
157 }
158 break;
159
160 case BLK_STATE_CLEAN:
161 /* Full (or almost full) of clean data. Clean list */
162 list_add(&jeb->list, &c->clean_list);
163 break;
164
165 case BLK_STATE_PARTDIRTY:
166 /* Some data, but not full. Dirty list. */
167 /* We want to remember the block with most free space
168 and stick it in the 'nextblock' position to start writing to it. */
169 if (jeb->free_size > min_free(c) &&
170 (!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
171 /* Better candidate for the next writes to go to */
172 if (c->nextblock) {
173 c->nextblock->dirty_size += c->nextblock->free_size + c->nextblock->wasted_size;
174 c->dirty_size += c->nextblock->free_size + c->nextblock->wasted_size;
175 c->free_size -= c->nextblock->free_size;
176 c->wasted_size -= c->nextblock->wasted_size;
177 c->nextblock->free_size = c->nextblock->wasted_size = 0;
178 if (VERYDIRTY(c, c->nextblock->dirty_size)) {
179 list_add(&c->nextblock->list, &c->very_dirty_list);
180 } else {
181 list_add(&c->nextblock->list, &c->dirty_list);
182 }
183 /* deleting summary information of the old nextblock */
184 jffs2_sum_reset_collected(c->summary);
185 }
186 /* update collected summary infromation for the current nextblock */
187 jffs2_sum_move_collected(c, s);
188 D1(printk(KERN_DEBUG "jffs2_scan_medium(): new nextblock = 0x%08x\n", jeb->offset));
189 c->nextblock = jeb;
190 } else {
191 jeb->dirty_size += jeb->free_size + jeb->wasted_size;
192 c->dirty_size += jeb->free_size + jeb->wasted_size;
193 c->free_size -= jeb->free_size;
194 c->wasted_size -= jeb->wasted_size;
195 jeb->free_size = jeb->wasted_size = 0;
196 if (VERYDIRTY(c, jeb->dirty_size)) {
197 list_add(&jeb->list, &c->very_dirty_list);
198 } else {
199 list_add(&jeb->list, &c->dirty_list);
200 }
201 }
202 break;
203
204 case BLK_STATE_ALLDIRTY:
205 /* Nothing valid - not even a clean marker. Needs erasing. */
206 /* For now we just put it on the erasing list. We'll start the erases later */
207 D1(printk(KERN_NOTICE "JFFS2: Erase block at 0x%08x is not formatted. It will be erased\n", jeb->offset));
208 list_add(&jeb->list, &c->erase_pending_list);
209 c->nr_erasing_blocks++;
210 break;
211
212 case BLK_STATE_BADBLOCK:
213 D1(printk(KERN_NOTICE "JFFS2: Block at 0x%08x is bad\n", jeb->offset));
214 list_add(&jeb->list, &c->bad_list);
215 c->bad_size += c->sector_size;
216 c->free_size -= c->sector_size;
217 bad_blocks++;
218 break;
219 default:
220 printk(KERN_WARNING "jffs2_scan_medium(): unknown block state\n");
221 BUG();
222 }
223 }
224
225 /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
226 if (c->nextblock && (c->nextblock->dirty_size)) {
227 c->nextblock->wasted_size += c->nextblock->dirty_size;
228 c->wasted_size += c->nextblock->dirty_size;
229 c->dirty_size -= c->nextblock->dirty_size;
230 c->nextblock->dirty_size = 0;
231 }
232 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
233 if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) {
234 /* If we're going to start writing into a block which already
235 contains data, and the end of the data isn't page-aligned,
236 skip a little and align it. */
237
238 uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize;
239
240 D1(printk(KERN_DEBUG "jffs2_scan_medium(): Skipping %d bytes in nextblock to ensure page alignment\n",
241 skip));
242 c->nextblock->wasted_size += skip;
243 c->wasted_size += skip;
244
245 c->nextblock->free_size -= skip;
246 c->free_size -= skip;
247 }
248 #endif
249 if (c->nr_erasing_blocks) {
250 if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) {
251 printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
252 printk(KERN_NOTICE "empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",empty_blocks,bad_blocks,c->nr_blocks);
253 ret = -EIO;
254 goto out;
255 }
256 jffs2_erase_pending_trigger(c);
257 }
258 ret = 0;
259 out:
260 if (buf_size)
261 kfree(flashbuf);
262 #ifndef __ECOS
263 else
264 c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size);
265 #endif
266 if (s)
267 kfree(s);
268
269 return ret;
270 }
271
272 int jffs2_fill_scan_buf (struct jffs2_sb_info *c, void *buf,
273 uint32_t ofs, uint32_t len)
274 {
275 int ret;
276 size_t retlen;
277
278 ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
279 if (ret) {
280 D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", len, ofs, ret));
281 return ret;
282 }
283 if (retlen < len) {
284 D1(printk(KERN_WARNING "Read at 0x%x gave only 0x%zx bytes\n", ofs, retlen));
285 return -EIO;
286 }
287 return 0;
288 }
289
290 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
291 {
292 if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
293 && (!jeb->first_node || !jeb->first_node->next_phys) )
294 return BLK_STATE_CLEANMARKER;
295
296 /* move blocks with max 4 byte dirty space to cleanlist */
297 else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
298 c->dirty_size -= jeb->dirty_size;
299 c->wasted_size += jeb->dirty_size;
300 jeb->wasted_size += jeb->dirty_size;
301 jeb->dirty_size = 0;
302 return BLK_STATE_CLEAN;
303 } else if (jeb->used_size || jeb->unchecked_size)
304 return BLK_STATE_PARTDIRTY;
305 else
306 return BLK_STATE_ALLDIRTY;
307 }
308
309 #ifdef CONFIG_JFFS2_FS_XATTR
310 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
311 struct jffs2_raw_xattr *rx, uint32_t ofs,
312 struct jffs2_summary *s)
313 {
314 struct jffs2_xattr_datum *xd;
315 struct jffs2_raw_node_ref *raw;
316 uint32_t totlen, crc;
317 int err;
318
319 crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
320 if (crc != je32_to_cpu(rx->node_crc)) {
321 if (je32_to_cpu(rx->node_crc) != 0xffffffff)
322 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
323 ofs, je32_to_cpu(rx->node_crc), crc);
324 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
325 return err;
326 return 0;
327 }
328
329 totlen = PAD(sizeof(*rx) + rx->name_len + 1 + je16_to_cpu(rx->value_len));
330 if (totlen != je32_to_cpu(rx->totlen)) {
331 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
332 ofs, je32_to_cpu(rx->totlen), totlen);
333 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
334 return err;
335 return 0;
336 }
337
338 raw = jffs2_alloc_raw_node_ref();
339 if (!raw)
340 return -ENOMEM;
341
342 xd = jffs2_setup_xattr_datum(c, je32_to_cpu(rx->xid), je32_to_cpu(rx->version));
343 if (IS_ERR(xd)) {
344 jffs2_free_raw_node_ref(raw);
345 if (PTR_ERR(xd) == -EEXIST) {
346 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rx->totlen)))))
347 return err;
348 return 0;
349 }
350 return PTR_ERR(xd);
351 }
352 xd->xprefix = rx->xprefix;
353 xd->name_len = rx->name_len;
354 xd->value_len = je16_to_cpu(rx->value_len);
355 xd->data_crc = je32_to_cpu(rx->data_crc);
356 xd->node = raw;
357
358 raw->flash_offset = ofs | REF_PRISTINE;
359 raw->next_in_ino = (void *)xd;
360
361 jffs2_link_node_ref(c, jeb, raw, totlen);
362
363 if (jffs2_sum_active())
364 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
365 dbg_xattr("scaning xdatum at %#08x (xid=%u, version=%u)\n",
366 ofs, xd->xid, xd->version);
367 return 0;
368 }
369
370 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
371 struct jffs2_raw_xref *rr, uint32_t ofs,
372 struct jffs2_summary *s)
373 {
374 struct jffs2_xattr_ref *ref;
375 struct jffs2_raw_node_ref *raw;
376 uint32_t crc;
377 int err;
378
379 crc = crc32(0, rr, sizeof(*rr) - 4);
380 if (crc != je32_to_cpu(rr->node_crc)) {
381 if (je32_to_cpu(rr->node_crc) != 0xffffffff)
382 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
383 ofs, je32_to_cpu(rr->node_crc), crc);
384 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
385 return err;
386 return 0;
387 }
388
389 if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
390 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
391 ofs, je32_to_cpu(rr->totlen),
392 PAD(sizeof(struct jffs2_raw_xref)));
393 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
394 return err;
395 return 0;
396 }
397
398 ref = jffs2_alloc_xattr_ref();
399 if (!ref)
400 return -ENOMEM;
401
402 raw = jffs2_alloc_raw_node_ref();
403 if (!raw) {
404 jffs2_free_xattr_ref(ref);
405 return -ENOMEM;
406 }
407
408 /* BEFORE jffs2_build_xattr_subsystem() called,
409 * ref->xid is used to store 32bit xid, xd is not used
410 * ref->ino is used to store 32bit inode-number, ic is not used
411 * Thoes variables are declared as union, thus using those
412 * are exclusive. In a similar way, ref->next is temporarily
413 * used to chain all xattr_ref object. It's re-chained to
414 * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
415 */
416 ref->node = raw;
417 ref->ino = je32_to_cpu(rr->ino);
418 ref->xid = je32_to_cpu(rr->xid);
419 ref->next = c->xref_temp;
420 c->xref_temp = ref;
421
422 raw->flash_offset = ofs | REF_PRISTINE;
423 raw->next_in_ino = (void *)ref;
424
425 jffs2_link_node_ref(c, jeb, raw, PAD(je32_to_cpu(rr->totlen)));
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 */
437 static 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;
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 = jffs2_check_nand_cleanmarker(c, jeb);
459 D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret));
460 /* Even if it's not found, we still scan to see
461 if the block is empty. We use this information
462 to decide whether to erase it or not. */
463 switch (ret) {
464 case 0: cleanmarkerfound = 1; break;
465 case 1: break;
466 case 2: return BLK_STATE_BADBLOCK;
467 case 3: return BLK_STATE_ALLDIRTY; /* Block has failed to erase min. once */
468 default: return ret;
469 }
470 }
471 #endif
472
473 if (jffs2_sum_active()) {
474 struct jffs2_sum_marker *sm;
475 void *sumptr = NULL;
476 uint32_t sumlen;
477
478 if (!buf_size) {
479 /* XIP case. Just look, point at the summary if it's there */
480 sm = (void *)buf + jeb->offset - sizeof(*sm);
481 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
482 sumptr = buf + je32_to_cpu(sm->offset);
483 sumlen = c->sector_size - je32_to_cpu(sm->offset);
484 }
485 } else {
486 /* If NAND flash, read a whole page of it. Else just the end */
487 if (c->wbuf_pagesize)
488 buf_len = c->wbuf_pagesize;
489 else
490 buf_len = sizeof(*sm);
491
492 /* Read as much as we want into the _end_ of the preallocated buffer */
493 err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len,
494 jeb->offset + c->sector_size - buf_len,
495 buf_len);
496 if (err)
497 return err;
498
499 sm = (void *)buf + buf_size - sizeof(*sm);
500 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
501 sumlen = c->sector_size - je32_to_cpu(sm->offset);
502 sumptr = buf + buf_size - sumlen;
503
504 /* Now, make sure the summary itself is available */
505 if (sumlen > buf_size) {
506 /* Need to kmalloc for this. */
507 sumptr = kmalloc(sumlen, GFP_KERNEL);
508 if (!sumptr)
509 return -ENOMEM;
510 memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
511 }
512 if (buf_len < sumlen) {
513 /* Need to read more so that the entire summary node is present */
514 err = jffs2_fill_scan_buf(c, sumptr,
515 jeb->offset + c->sector_size - sumlen,
516 sumlen - buf_len);
517 if (err)
518 return err;
519 }
520 }
521
522 }
523
524 if (sumptr) {
525 err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
526
527 if (buf_size && sumlen > buf_size)
528 kfree(sumptr);
529 /* If it returns with a real error, bail.
530 If it returns positive, that's a block classification
531 (i.e. BLK_STATE_xxx) so return that too.
532 If it returns zero, fall through to full scan. */
533 if (err)
534 return err;
535 }
536 }
537
538 buf_ofs = jeb->offset;
539
540 if (!buf_size) {
541 /* This is the XIP case -- we're reading _directly_ from the flash chip */
542 buf_len = c->sector_size;
543 } else {
544 buf_len = EMPTY_SCAN_SIZE(c->sector_size);
545 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
546 if (err)
547 return err;
548 }
549
550 /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
551 ofs = 0;
552
553 /* Scan only 4KiB of 0xFF before declaring it's empty */
554 while(ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
555 ofs += 4;
556
557 if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) {
558 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
559 if (jffs2_cleanmarker_oob(c)) {
560 /* scan oob, take care of cleanmarker */
561 int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
562 D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret));
563 switch (ret) {
564 case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
565 case 1: return BLK_STATE_ALLDIRTY;
566 default: return ret;
567 }
568 }
569 #endif
570 D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset));
571 if (c->cleanmarker_size == 0)
572 return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */
573 else
574 return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
575 }
576 if (ofs) {
577 D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset,
578 jeb->offset + ofs));
579 if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
580 return err;
581 }
582
583 /* Now ofs is a complete physical flash offset as it always was... */
584 ofs += jeb->offset;
585
586 noise = 10;
587
588 dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
589
590 scan_more:
591 while(ofs < jeb->offset + c->sector_size) {
592
593 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
594
595 cond_resched();
596
597 if (ofs & 3) {
598 printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs);
599 ofs = PAD(ofs);
600 continue;
601 }
602 if (ofs == prevofs) {
603 printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs);
604 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
605 return err;
606 ofs += 4;
607 continue;
608 }
609 prevofs = ofs;
610
611 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
612 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),
613 jeb->offset, c->sector_size, ofs, sizeof(*node)));
614 if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
615 return err;
616 break;
617 }
618
619 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
620 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
621 D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
622 sizeof(struct jffs2_unknown_node), buf_len, ofs));
623 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
624 if (err)
625 return err;
626 buf_ofs = ofs;
627 }
628
629 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
630
631 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
632 uint32_t inbuf_ofs;
633 uint32_t empty_start;
634
635 empty_start = ofs;
636 ofs += 4;
637
638 D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs));
639 more_empty:
640 inbuf_ofs = ofs - buf_ofs;
641 while (inbuf_ofs < buf_len) {
642 if (*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff) {
643 printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n",
644 empty_start, ofs);
645 if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
646 return err;
647 goto scan_more;
648 }
649
650 inbuf_ofs+=4;
651 ofs += 4;
652 }
653 /* Ran off end. */
654 D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs));
655
656 /* If we're only checking the beginning of a block with a cleanmarker,
657 bail now */
658 if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
659 c->cleanmarker_size && !jeb->dirty_size && !jeb->first_node->next_phys) {
660 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size)));
661 return BLK_STATE_CLEANMARKER;
662 }
663
664 /* See how much more there is to read in this eraseblock... */
665 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
666 if (!buf_len) {
667 /* No more to read. Break out of main loop without marking
668 this range of empty space as dirty (because it's not) */
669 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n",
670 empty_start));
671 break;
672 }
673 D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs));
674 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
675 if (err)
676 return err;
677 buf_ofs = ofs;
678 goto more_empty;
679 }
680
681 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
682 printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs);
683 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
684 return err;
685 ofs += 4;
686 continue;
687 }
688 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
689 D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs));
690 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
691 return err;
692 ofs += 4;
693 continue;
694 }
695 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
696 printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs);
697 printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n");
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_MAGIC_BITMASK) {
704 /* OK. We're out of possibilities. Whinge and move on */
705 noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
706 JFFS2_MAGIC_BITMASK, ofs,
707 je16_to_cpu(node->magic));
708 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
709 return err;
710 ofs += 4;
711 continue;
712 }
713 /* We seem to have a node of sorts. Check the CRC */
714 crcnode.magic = node->magic;
715 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
716 crcnode.totlen = node->totlen;
717 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
718
719 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
720 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",
721 ofs, je16_to_cpu(node->magic),
722 je16_to_cpu(node->nodetype),
723 je32_to_cpu(node->totlen),
724 je32_to_cpu(node->hdr_crc),
725 hdr_crc);
726 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
727 return err;
728 ofs += 4;
729 continue;
730 }
731
732 if (ofs + je32_to_cpu(node->totlen) >
733 jeb->offset + c->sector_size) {
734 /* Eep. Node goes over the end of the erase block. */
735 printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
736 ofs, je32_to_cpu(node->totlen));
737 printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
738 if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
739 return err;
740 ofs += 4;
741 continue;
742 }
743
744 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
745 /* Wheee. This is an obsoleted node */
746 D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));
747 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
748 return err;
749 ofs += PAD(je32_to_cpu(node->totlen));
750 continue;
751 }
752
753 switch(je16_to_cpu(node->nodetype)) {
754 case JFFS2_NODETYPE_INODE:
755 if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
756 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
757 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
758 sizeof(struct jffs2_raw_inode), buf_len, ofs));
759 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
760 if (err)
761 return err;
762 buf_ofs = ofs;
763 node = (void *)buf;
764 }
765 err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
766 if (err) return err;
767 ofs += PAD(je32_to_cpu(node->totlen));
768 break;
769
770 case JFFS2_NODETYPE_DIRENT:
771 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
772 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
773 D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
774 je32_to_cpu(node->totlen), buf_len, ofs));
775 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
776 if (err)
777 return err;
778 buf_ofs = ofs;
779 node = (void *)buf;
780 }
781 err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
782 if (err) return err;
783 ofs += PAD(je32_to_cpu(node->totlen));
784 break;
785
786 #ifdef CONFIG_JFFS2_FS_XATTR
787 case JFFS2_NODETYPE_XATTR:
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 (xattr node)"
791 " left to end of buf. Reading 0x%x at 0x%08x\n",
792 je32_to_cpu(node->totlen), buf_len, ofs));
793 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
794 if (err)
795 return err;
796 buf_ofs = ofs;
797 node = (void *)buf;
798 }
799 err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
800 if (err)
801 return err;
802 ofs += PAD(je32_to_cpu(node->totlen));
803 break;
804 case JFFS2_NODETYPE_XREF:
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 (xref 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_xref_node(c, jeb, (void *)node, ofs, s);
817 if (err)
818 return err;
819 ofs += PAD(je32_to_cpu(node->totlen));
820 break;
821 #endif /* CONFIG_JFFS2_FS_XATTR */
822
823 case JFFS2_NODETYPE_CLEANMARKER:
824 D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs));
825 if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
826 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
827 ofs, je32_to_cpu(node->totlen), c->cleanmarker_size);
828 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
829 return err;
830 ofs += PAD(sizeof(struct jffs2_unknown_node));
831 } else if (jeb->first_node) {
832 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset);
833 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
834 return err;
835 ofs += PAD(sizeof(struct jffs2_unknown_node));
836 } else {
837 struct jffs2_raw_node_ref *marker_ref = jffs2_alloc_raw_node_ref();
838 if (!marker_ref) {
839 printk(KERN_NOTICE "Failed to allocate node ref for clean marker\n");
840 return -ENOMEM;
841 }
842 marker_ref->next_in_ino = NULL;
843 marker_ref->flash_offset = ofs | REF_NORMAL;
844
845 jffs2_link_node_ref(c, jeb, marker_ref, c->cleanmarker_size);
846
847 ofs += PAD(c->cleanmarker_size);
848 }
849 break;
850
851 case JFFS2_NODETYPE_PADDING:
852 if (jffs2_sum_active())
853 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
854 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
855 return err;
856 ofs += PAD(je32_to_cpu(node->totlen));
857 break;
858
859 default:
860 switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
861 case JFFS2_FEATURE_ROCOMPAT:
862 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
863 c->flags |= JFFS2_SB_FLAG_RO;
864 if (!(jffs2_is_readonly(c)))
865 return -EROFS;
866 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
867 return err;
868 ofs += PAD(je32_to_cpu(node->totlen));
869 break;
870
871 case JFFS2_FEATURE_INCOMPAT:
872 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
873 return -EINVAL;
874
875 case JFFS2_FEATURE_RWCOMPAT_DELETE:
876 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
877 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
878 return err;
879 ofs += PAD(je32_to_cpu(node->totlen));
880 break;
881
882 case JFFS2_FEATURE_RWCOMPAT_COPY: {
883 struct jffs2_raw_node_ref *ref;
884 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
885
886 ref = jffs2_alloc_raw_node_ref();
887 if (!ref)
888 return -ENOMEM;
889 ref->flash_offset = ofs | REF_PRISTINE;
890 ref->next_in_ino = 0;
891 jffs2_link_node_ref(c, jeb, ref, PAD(je32_to_cpu(node->totlen)));
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\n", jeb->offset,
911 jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_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->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_raw_node_ref *raw;
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 raw = jffs2_alloc_raw_node_ref();
970 if (!raw) {
971 printk(KERN_NOTICE "jffs2_scan_inode_node(): allocation of node reference failed\n");
972 return -ENOMEM;
973 }
974
975 ic = jffs2_get_ino_cache(c, ino);
976 if (!ic) {
977 /* Inocache get failed. Either we read a bogus ino# or it's just genuinely the
978 first node we found for this inode. Do a CRC check to protect against the former
979 case */
980 uint32_t crc = crc32(0, ri, sizeof(*ri)-8);
981
982 if (crc != je32_to_cpu(ri->node_crc)) {
983 printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
984 ofs, je32_to_cpu(ri->node_crc), crc);
985 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
986 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(ri->totlen)))))
987 return err;
988 jffs2_free_raw_node_ref(raw);
989 return 0;
990 }
991 ic = jffs2_scan_make_ino_cache(c, ino);
992 if (!ic) {
993 jffs2_free_raw_node_ref(raw);
994 return -ENOMEM;
995 }
996 }
997
998 /* Wheee. It worked */
999
1000 raw->flash_offset = ofs | REF_UNCHECKED;
1001
1002 raw->next_in_ino = ic->nodes;
1003 ic->nodes = raw;
1004
1005 jffs2_link_node_ref(c, jeb, raw, PAD(je32_to_cpu(ri->totlen)));
1006
1007 D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
1008 je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
1009 je32_to_cpu(ri->offset),
1010 je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)));
1011
1012 pseudo_random += je32_to_cpu(ri->version);
1013
1014 if (jffs2_sum_active()) {
1015 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
1016 }
1017
1018 return 0;
1019 }
1020
1021 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
1022 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
1023 {
1024 struct jffs2_raw_node_ref *raw;
1025 struct jffs2_full_dirent *fd;
1026 struct jffs2_inode_cache *ic;
1027 uint32_t crc;
1028 int err;
1029
1030 D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs));
1031
1032 /* We don't get here unless the node is still valid, so we don't have to
1033 mask in the ACCURATE bit any more. */
1034 crc = crc32(0, rd, sizeof(*rd)-8);
1035
1036 if (crc != je32_to_cpu(rd->node_crc)) {
1037 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1038 ofs, je32_to_cpu(rd->node_crc), crc);
1039 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1040 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1041 return err;
1042 return 0;
1043 }
1044
1045 pseudo_random += je32_to_cpu(rd->version);
1046
1047 fd = jffs2_alloc_full_dirent(rd->nsize+1);
1048 if (!fd) {
1049 return -ENOMEM;
1050 }
1051 memcpy(&fd->name, rd->name, rd->nsize);
1052 fd->name[rd->nsize] = 0;
1053
1054 crc = crc32(0, fd->name, rd->nsize);
1055 if (crc != je32_to_cpu(rd->name_crc)) {
1056 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1057 ofs, je32_to_cpu(rd->name_crc), crc);
1058 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino)));
1059 jffs2_free_full_dirent(fd);
1060 /* FIXME: Why do we believe totlen? */
1061 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1062 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1063 return err;
1064 return 0;
1065 }
1066 raw = jffs2_alloc_raw_node_ref();
1067 if (!raw) {
1068 jffs2_free_full_dirent(fd);
1069 printk(KERN_NOTICE "jffs2_scan_dirent_node(): allocation of node reference failed\n");
1070 return -ENOMEM;
1071 }
1072 ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1073 if (!ic) {
1074 jffs2_free_full_dirent(fd);
1075 jffs2_free_raw_node_ref(raw);
1076 return -ENOMEM;
1077 }
1078
1079 raw->flash_offset = ofs | REF_PRISTINE;
1080 raw->next_in_ino = ic->nodes;
1081 ic->nodes = raw;
1082
1083 jffs2_link_node_ref(c, jeb, raw, PAD(je32_to_cpu(rd->totlen)));
1084
1085 fd->raw = raw;
1086 fd->next = NULL;
1087 fd->version = je32_to_cpu(rd->version);
1088 fd->ino = je32_to_cpu(rd->ino);
1089 fd->nhash = full_name_hash(fd->name, rd->nsize);
1090 fd->type = rd->type;
1091 jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1092
1093 if (jffs2_sum_active()) {
1094 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1095 }
1096
1097 return 0;
1098 }
1099
1100 static int count_list(struct list_head *l)
1101 {
1102 uint32_t count = 0;
1103 struct list_head *tmp;
1104
1105 list_for_each(tmp, l) {
1106 count++;
1107 }
1108 return count;
1109 }
1110
1111 /* Note: This breaks if list_empty(head). I don't care. You
1112 might, if you copy this code and use it elsewhere :) */
1113 static void rotate_list(struct list_head *head, uint32_t count)
1114 {
1115 struct list_head *n = head->next;
1116
1117 list_del(head);
1118 while(count--) {
1119 n = n->next;
1120 }
1121 list_add(head, n);
1122 }
1123
1124 void jffs2_rotate_lists(struct jffs2_sb_info *c)
1125 {
1126 uint32_t x;
1127 uint32_t rotateby;
1128
1129 x = count_list(&c->clean_list);
1130 if (x) {
1131 rotateby = pseudo_random % x;
1132 rotate_list((&c->clean_list), rotateby);
1133 }
1134
1135 x = count_list(&c->very_dirty_list);
1136 if (x) {
1137 rotateby = pseudo_random % x;
1138 rotate_list((&c->very_dirty_list), rotateby);
1139 }
1140
1141 x = count_list(&c->dirty_list);
1142 if (x) {
1143 rotateby = pseudo_random % x;
1144 rotate_list((&c->dirty_list), rotateby);
1145 }
1146
1147 x = count_list(&c->erasable_list);
1148 if (x) {
1149 rotateby = pseudo_random % x;
1150 rotate_list((&c->erasable_list), rotateby);
1151 }
1152
1153 if (c->nr_erasing_blocks) {
1154 rotateby = pseudo_random % c->nr_erasing_blocks;
1155 rotate_list((&c->erase_pending_list), rotateby);
1156 }
1157
1158 if (c->nr_free_blocks) {
1159 rotateby = pseudo_random % c->nr_free_blocks;
1160 rotate_list((&c->free_list), rotateby);
1161 }
1162 }
SocketAccessConTroL development