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