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 1024 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 jffs2_erase_pending_trigger(c); 264 } 265 ret = 0; 266 out: 267 if (buf_size) 268 kfree(flashbuf); 269 #ifndef __ECOS 270 else 271 c->mtd->unpoint(c->mtd, 0, c->mtd->size); 272 #endif 273 if (s) 274 kfree(s); 275 276 return ret; 277 } 278 279 static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf, 280 uint32_t ofs, uint32_t len) 281 { 282 int ret; 283 size_t retlen; 284 285 ret = jffs2_flash_read(c, ofs, len, &retlen, buf); 286 if (ret) { 287 D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", len, ofs, ret)); 288 return ret; 289 } 290 if (retlen < len) { 291 D1(printk(KERN_WARNING "Read at 0x%x gave only 0x%zx bytes\n", ofs, retlen)); 292 return -EIO; 293 } 294 return 0; 295 } 296 297 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb) 298 { 299 if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size 300 && (!jeb->first_node || !ref_next(jeb->first_node)) ) 301 return BLK_STATE_CLEANMARKER; 302 303 /* move blocks with max 4 byte dirty space to cleanlist */ 304 else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) { 305 c->dirty_size -= jeb->dirty_size; 306 c->wasted_size += jeb->dirty_size; 307 jeb->wasted_size += jeb->dirty_size; 308 jeb->dirty_size = 0; 309 return BLK_STATE_CLEAN; 310 } else if (jeb->used_size || jeb->unchecked_size) 311 return BLK_STATE_PARTDIRTY; 312 else 313 return BLK_STATE_ALLDIRTY; 314 } 315 316 #ifdef CONFIG_JFFS2_FS_XATTR 317 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 318 struct jffs2_raw_xattr *rx, uint32_t ofs, 319 struct jffs2_summary *s) 320 { 321 struct jffs2_xattr_datum *xd; 322 uint32_t xid, version, totlen, crc; 323 int err; 324 325 crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4); 326 if (crc != je32_to_cpu(rx->node_crc)) { 327 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n", 328 ofs, je32_to_cpu(rx->node_crc), crc); 329 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen)))) 330 return err; 331 return 0; 332 } 333 334 xid = je32_to_cpu(rx->xid); 335 version = je32_to_cpu(rx->version); 336 337 totlen = PAD(sizeof(struct jffs2_raw_xattr) 338 + rx->name_len + 1 + je16_to_cpu(rx->value_len)); 339 if (totlen != je32_to_cpu(rx->totlen)) { 340 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n", 341 ofs, je32_to_cpu(rx->totlen), totlen); 342 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen)))) 343 return err; 344 return 0; 345 } 346 347 xd = jffs2_setup_xattr_datum(c, xid, version); 348 if (IS_ERR(xd)) 349 return PTR_ERR(xd); 350 351 if (xd->version > version) { 352 struct jffs2_raw_node_ref *raw 353 = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL); 354 raw->next_in_ino = xd->node->next_in_ino; 355 xd->node->next_in_ino = raw; 356 } else { 357 xd->version = version; 358 xd->xprefix = rx->xprefix; 359 xd->name_len = rx->name_len; 360 xd->value_len = je16_to_cpu(rx->value_len); 361 xd->data_crc = je32_to_cpu(rx->data_crc); 362 363 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd); 364 } 365 366 if (jffs2_sum_active()) 367 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset); 368 dbg_xattr("scaning xdatum at %#08x (xid=%u, version=%u)\n", 369 ofs, xd->xid, xd->version); 370 return 0; 371 } 372 373 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 374 struct jffs2_raw_xref *rr, uint32_t ofs, 375 struct jffs2_summary *s) 376 { 377 struct jffs2_xattr_ref *ref; 378 uint32_t crc; 379 int err; 380 381 crc = crc32(0, rr, sizeof(*rr) - 4); 382 if (crc != je32_to_cpu(rr->node_crc)) { 383 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n", 384 ofs, je32_to_cpu(rr->node_crc), crc); 385 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen))))) 386 return err; 387 return 0; 388 } 389 390 if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) { 391 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n", 392 ofs, je32_to_cpu(rr->totlen), 393 PAD(sizeof(struct jffs2_raw_xref))); 394 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen)))) 395 return err; 396 return 0; 397 } 398 399 ref = jffs2_alloc_xattr_ref(); 400 if (!ref) 401 return -ENOMEM; 402 403 /* BEFORE jffs2_build_xattr_subsystem() called, 404 * and AFTER xattr_ref is marked as a dead xref, 405 * ref->xid is used to store 32bit xid, xd is not used 406 * ref->ino is used to store 32bit inode-number, ic is not used 407 * Thoes variables are declared as union, thus using those 408 * are exclusive. In a similar way, ref->next is temporarily 409 * used to chain all xattr_ref object. It's re-chained to 410 * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly. 411 */ 412 ref->ino = je32_to_cpu(rr->ino); 413 ref->xid = je32_to_cpu(rr->xid); 414 ref->xseqno = je32_to_cpu(rr->xseqno); 415 if (ref->xseqno > c->highest_xseqno) 416 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER); 417 ref->next = c->xref_temp; 418 c->xref_temp = ref; 419 420 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref); 421 422 if (jffs2_sum_active()) 423 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset); 424 dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n", 425 ofs, ref->xid, ref->ino); 426 return 0; 427 } 428 #endif 429 430 /* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into 431 the flash, XIP-style */ 432 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 433 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) { 434 struct jffs2_unknown_node *node; 435 struct jffs2_unknown_node crcnode; 436 uint32_t ofs, prevofs; 437 uint32_t hdr_crc, buf_ofs, buf_len; 438 int err; 439 int noise = 0; 440 441 442 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 443 int cleanmarkerfound = 0; 444 #endif 445 446 ofs = jeb->offset; 447 prevofs = jeb->offset - 1; 448 449 D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs)); 450 451 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 452 if (jffs2_cleanmarker_oob(c)) { 453 int ret; 454 455 if (c->mtd->block_isbad(c->mtd, jeb->offset)) 456 return BLK_STATE_BADBLOCK; 457 458 ret = jffs2_check_nand_cleanmarker(c, jeb); 459 D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret)); 460 461 /* Even if it's not found, we still scan to see 462 if the block is empty. We use this information 463 to decide whether to erase it or not. */ 464 switch (ret) { 465 case 0: cleanmarkerfound = 1; break; 466 case 1: break; 467 default: return ret; 468 } 469 } 470 #endif 471 472 if (jffs2_sum_active()) { 473 struct jffs2_sum_marker *sm; 474 void *sumptr = NULL; 475 uint32_t sumlen; 476 477 if (!buf_size) { 478 /* XIP case. Just look, point at the summary if it's there */ 479 sm = (void *)buf + c->sector_size - sizeof(*sm); 480 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) { 481 sumptr = buf + je32_to_cpu(sm->offset); 482 sumlen = c->sector_size - je32_to_cpu(sm->offset); 483 } 484 } else { 485 /* If NAND flash, read a whole page of it. Else just the end */ 486 if (c->wbuf_pagesize) 487 buf_len = c->wbuf_pagesize; 488 else 489 buf_len = sizeof(*sm); 490 491 /* Read as much as we want into the _end_ of the preallocated buffer */ 492 err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, 493 jeb->offset + c->sector_size - buf_len, 494 buf_len); 495 if (err) 496 return err; 497 498 sm = (void *)buf + buf_size - sizeof(*sm); 499 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) { 500 sumlen = c->sector_size - je32_to_cpu(sm->offset); 501 sumptr = buf + buf_size - sumlen; 502 503 /* Now, make sure the summary itself is available */ 504 if (sumlen > buf_size) { 505 /* Need to kmalloc for this. */ 506 sumptr = kmalloc(sumlen, GFP_KERNEL); 507 if (!sumptr) 508 return -ENOMEM; 509 memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len); 510 } 511 if (buf_len < sumlen) { 512 /* Need to read more so that the entire summary node is present */ 513 err = jffs2_fill_scan_buf(c, sumptr, 514 jeb->offset + c->sector_size - sumlen, 515 sumlen - buf_len); 516 if (err) 517 return err; 518 } 519 } 520 521 } 522 523 if (sumptr) { 524 err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random); 525 526 if (buf_size && sumlen > buf_size) 527 kfree(sumptr); 528 /* If it returns with a real error, bail. 529 If it returns positive, that's a block classification 530 (i.e. BLK_STATE_xxx) so return that too. 531 If it returns zero, fall through to full scan. */ 532 if (err) 533 return err; 534 } 535 } 536 537 buf_ofs = jeb->offset; 538 539 if (!buf_size) { 540 /* This is the XIP case -- we're reading _directly_ from the flash chip */ 541 buf_len = c->sector_size; 542 } else { 543 buf_len = EMPTY_SCAN_SIZE(c->sector_size); 544 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len); 545 if (err) 546 return err; 547 } 548 549 /* We temporarily use 'ofs' as a pointer into the buffer/jeb */ 550 ofs = 0; 551 552 /* Scan only 4KiB of 0xFF before declaring it's empty */ 553 while(ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF) 554 ofs += 4; 555 556 if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) { 557 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 558 if (jffs2_cleanmarker_oob(c)) { 559 /* scan oob, take care of cleanmarker */ 560 int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound); 561 D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret)); 562 switch (ret) { 563 case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF; 564 case 1: return BLK_STATE_ALLDIRTY; 565 default: return ret; 566 } 567 } 568 #endif 569 D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset)); 570 if (c->cleanmarker_size == 0) 571 return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */ 572 else 573 return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */ 574 } 575 if (ofs) { 576 D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset, 577 jeb->offset + ofs)); 578 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1))) 579 return err; 580 if ((err = jffs2_scan_dirty_space(c, jeb, ofs))) 581 return err; 582 } 583 584 /* Now ofs is a complete physical flash offset as it always was... */ 585 ofs += jeb->offset; 586 587 noise = 10; 588 589 dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset); 590 591 scan_more: 592 while(ofs < jeb->offset + c->sector_size) { 593 594 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 595 596 /* Make sure there are node refs available for use */ 597 err = jffs2_prealloc_raw_node_refs(c, jeb, 2); 598 if (err) 599 return err; 600 601 cond_resched(); 602 603 if (ofs & 3) { 604 printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs); 605 ofs = PAD(ofs); 606 continue; 607 } 608 if (ofs == prevofs) { 609 printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs); 610 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 611 return err; 612 ofs += 4; 613 continue; 614 } 615 prevofs = ofs; 616 617 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) { 618 D1(printk(KERN_DEBUG "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n", sizeof(struct jffs2_unknown_node), 619 jeb->offset, c->sector_size, ofs, sizeof(*node))); 620 if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs))) 621 return err; 622 break; 623 } 624 625 if (buf_ofs + buf_len < ofs + sizeof(*node)) { 626 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 627 D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n", 628 sizeof(struct jffs2_unknown_node), buf_len, ofs)); 629 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 630 if (err) 631 return err; 632 buf_ofs = ofs; 633 } 634 635 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs]; 636 637 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) { 638 uint32_t inbuf_ofs; 639 uint32_t empty_start, scan_end; 640 641 empty_start = ofs; 642 ofs += 4; 643 scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len); 644 645 D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs)); 646 more_empty: 647 inbuf_ofs = ofs - buf_ofs; 648 while (inbuf_ofs < scan_end) { 649 if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) { 650 printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n", 651 empty_start, ofs); 652 if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start))) 653 return err; 654 goto scan_more; 655 } 656 657 inbuf_ofs+=4; 658 ofs += 4; 659 } 660 /* Ran off end. */ 661 D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs)); 662 663 /* If we're only checking the beginning of a block with a cleanmarker, 664 bail now */ 665 if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) && 666 c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) { 667 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size))); 668 return BLK_STATE_CLEANMARKER; 669 } 670 if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */ 671 scan_end = buf_len; 672 goto more_empty; 673 } 674 675 /* See how much more there is to read in this eraseblock... */ 676 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 677 if (!buf_len) { 678 /* No more to read. Break out of main loop without marking 679 this range of empty space as dirty (because it's not) */ 680 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n", 681 empty_start)); 682 break; 683 } 684 /* point never reaches here */ 685 scan_end = buf_len; 686 D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs)); 687 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 688 if (err) 689 return err; 690 buf_ofs = ofs; 691 goto more_empty; 692 } 693 694 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) { 695 printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs); 696 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 697 return err; 698 ofs += 4; 699 continue; 700 } 701 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) { 702 D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs)); 703 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 704 return err; 705 ofs += 4; 706 continue; 707 } 708 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) { 709 printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs); 710 printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n"); 711 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 712 return err; 713 ofs += 4; 714 continue; 715 } 716 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) { 717 /* OK. We're out of possibilities. Whinge and move on */ 718 noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n", 719 JFFS2_MAGIC_BITMASK, ofs, 720 je16_to_cpu(node->magic)); 721 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 722 return err; 723 ofs += 4; 724 continue; 725 } 726 /* We seem to have a node of sorts. Check the CRC */ 727 crcnode.magic = node->magic; 728 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE); 729 crcnode.totlen = node->totlen; 730 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4); 731 732 if (hdr_crc != je32_to_cpu(node->hdr_crc)) { 733 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", 734 ofs, je16_to_cpu(node->magic), 735 je16_to_cpu(node->nodetype), 736 je32_to_cpu(node->totlen), 737 je32_to_cpu(node->hdr_crc), 738 hdr_crc); 739 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 740 return err; 741 ofs += 4; 742 continue; 743 } 744 745 if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) { 746 /* Eep. Node goes over the end of the erase block. */ 747 printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n", 748 ofs, je32_to_cpu(node->totlen)); 749 printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n"); 750 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 751 return err; 752 ofs += 4; 753 continue; 754 } 755 756 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) { 757 /* Wheee. This is an obsoleted node */ 758 D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs)); 759 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 760 return err; 761 ofs += PAD(je32_to_cpu(node->totlen)); 762 continue; 763 } 764 765 switch(je16_to_cpu(node->nodetype)) { 766 case JFFS2_NODETYPE_INODE: 767 if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) { 768 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 769 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n", 770 sizeof(struct jffs2_raw_inode), buf_len, ofs)); 771 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 772 if (err) 773 return err; 774 buf_ofs = ofs; 775 node = (void *)buf; 776 } 777 err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s); 778 if (err) return err; 779 ofs += PAD(je32_to_cpu(node->totlen)); 780 break; 781 782 case JFFS2_NODETYPE_DIRENT: 783 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 784 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 785 D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n", 786 je32_to_cpu(node->totlen), buf_len, ofs)); 787 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 788 if (err) 789 return err; 790 buf_ofs = ofs; 791 node = (void *)buf; 792 } 793 err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s); 794 if (err) return err; 795 ofs += PAD(je32_to_cpu(node->totlen)); 796 break; 797 798 #ifdef CONFIG_JFFS2_FS_XATTR 799 case JFFS2_NODETYPE_XATTR: 800 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 801 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 802 D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)" 803 " left to end of buf. Reading 0x%x at 0x%08x\n", 804 je32_to_cpu(node->totlen), buf_len, ofs)); 805 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 806 if (err) 807 return err; 808 buf_ofs = ofs; 809 node = (void *)buf; 810 } 811 err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s); 812 if (err) 813 return err; 814 ofs += PAD(je32_to_cpu(node->totlen)); 815 break; 816 case JFFS2_NODETYPE_XREF: 817 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 818 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 819 D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)" 820 " left to end of buf. Reading 0x%x at 0x%08x\n", 821 je32_to_cpu(node->totlen), buf_len, ofs)); 822 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 823 if (err) 824 return err; 825 buf_ofs = ofs; 826 node = (void *)buf; 827 } 828 err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s); 829 if (err) 830 return err; 831 ofs += PAD(je32_to_cpu(node->totlen)); 832 break; 833 #endif /* CONFIG_JFFS2_FS_XATTR */ 834 835 case JFFS2_NODETYPE_CLEANMARKER: 836 D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs)); 837 if (je32_to_cpu(node->totlen) != c->cleanmarker_size) { 838 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n", 839 ofs, je32_to_cpu(node->totlen), c->cleanmarker_size); 840 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node))))) 841 return err; 842 ofs += PAD(sizeof(struct jffs2_unknown_node)); 843 } else if (jeb->first_node) { 844 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset); 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 { 849 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL); 850 851 ofs += PAD(c->cleanmarker_size); 852 } 853 break; 854 855 case JFFS2_NODETYPE_PADDING: 856 if (jffs2_sum_active()) 857 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen)); 858 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 859 return err; 860 ofs += PAD(je32_to_cpu(node->totlen)); 861 break; 862 863 default: 864 switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) { 865 case JFFS2_FEATURE_ROCOMPAT: 866 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs); 867 c->flags |= JFFS2_SB_FLAG_RO; 868 if (!(jffs2_is_readonly(c))) 869 return -EROFS; 870 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 871 return err; 872 ofs += PAD(je32_to_cpu(node->totlen)); 873 break; 874 875 case JFFS2_FEATURE_INCOMPAT: 876 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs); 877 return -EINVAL; 878 879 case JFFS2_FEATURE_RWCOMPAT_DELETE: 880 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs)); 881 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 882 return err; 883 ofs += PAD(je32_to_cpu(node->totlen)); 884 break; 885 886 case JFFS2_FEATURE_RWCOMPAT_COPY: { 887 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs)); 888 889 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL); 890 891 /* We can't summarise nodes we don't grok */ 892 jffs2_sum_disable_collecting(s); 893 ofs += PAD(je32_to_cpu(node->totlen)); 894 break; 895 } 896 } 897 } 898 } 899 900 if (jffs2_sum_active()) { 901 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) { 902 dbg_summary("There is not enough space for " 903 "summary information, disabling for this jeb!\n"); 904 jffs2_sum_disable_collecting(s); 905 } 906 } 907 908 D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n", 909 jeb->offset,jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size, jeb->wasted_size)); 910 911 /* mark_node_obsolete can add to wasted !! */ 912 if (jeb->wasted_size) { 913 jeb->dirty_size += jeb->wasted_size; 914 c->dirty_size += jeb->wasted_size; 915 c->wasted_size -= jeb->wasted_size; 916 jeb->wasted_size = 0; 917 } 918 919 return jffs2_scan_classify_jeb(c, jeb); 920 } 921 922 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino) 923 { 924 struct jffs2_inode_cache *ic; 925 926 ic = jffs2_get_ino_cache(c, ino); 927 if (ic) 928 return ic; 929 930 if (ino > c->highest_ino) 931 c->highest_ino = ino; 932 933 ic = jffs2_alloc_inode_cache(); 934 if (!ic) { 935 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n"); 936 return NULL; 937 } 938 memset(ic, 0, sizeof(*ic)); 939 940 ic->ino = ino; 941 ic->nodes = (void *)ic; 942 jffs2_add_ino_cache(c, ic); 943 if (ino == 1) 944 ic->pino_nlink = 1; 945 return ic; 946 } 947 948 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 949 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s) 950 { 951 struct jffs2_inode_cache *ic; 952 uint32_t crc, ino = je32_to_cpu(ri->ino); 953 954 D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs)); 955 956 /* We do very little here now. Just check the ino# to which we should attribute 957 this node; we can do all the CRC checking etc. later. There's a tradeoff here -- 958 we used to scan the flash once only, reading everything we want from it into 959 memory, then building all our in-core data structures and freeing the extra 960 information. Now we allow the first part of the mount to complete a lot quicker, 961 but we have to go _back_ to the flash in order to finish the CRC checking, etc. 962 Which means that the _full_ amount of time to get to proper write mode with GC 963 operational may actually be _longer_ than before. Sucks to be me. */ 964 965 /* Check the node CRC in any case. */ 966 crc = crc32(0, ri, sizeof(*ri)-8); 967 if (crc != je32_to_cpu(ri->node_crc)) { 968 printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on " 969 "node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 970 ofs, je32_to_cpu(ri->node_crc), crc); 971 /* 972 * We believe totlen because the CRC on the node 973 * _header_ was OK, just the node itself failed. 974 */ 975 return jffs2_scan_dirty_space(c, jeb, 976 PAD(je32_to_cpu(ri->totlen))); 977 } 978 979 ic = jffs2_get_ino_cache(c, ino); 980 if (!ic) { 981 ic = jffs2_scan_make_ino_cache(c, ino); 982 if (!ic) 983 return -ENOMEM; 984 } 985 986 /* Wheee. It worked */ 987 jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic); 988 989 D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n", 990 je32_to_cpu(ri->ino), je32_to_cpu(ri->version), 991 je32_to_cpu(ri->offset), 992 je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize))); 993 994 pseudo_random += je32_to_cpu(ri->version); 995 996 if (jffs2_sum_active()) { 997 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset); 998 } 999 1000 return 0; 1001 } 1002 1003 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 1004 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s) 1005 { 1006 struct jffs2_full_dirent *fd; 1007 struct jffs2_inode_cache *ic; 1008 uint32_t checkedlen; 1009 uint32_t crc; 1010 int err; 1011 1012 D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs)); 1013 1014 /* We don't get here unless the node is still valid, so we don't have to 1015 mask in the ACCURATE bit any more. */ 1016 crc = crc32(0, rd, sizeof(*rd)-8); 1017 1018 if (crc != je32_to_cpu(rd->node_crc)) { 1019 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1020 ofs, je32_to_cpu(rd->node_crc), crc); 1021 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */ 1022 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen))))) 1023 return err; 1024 return 0; 1025 } 1026 1027 pseudo_random += je32_to_cpu(rd->version); 1028 1029 /* Should never happen. Did. (OLPC trac #4184)*/ 1030 checkedlen = strnlen(rd->name, rd->nsize); 1031 if (checkedlen < rd->nsize) { 1032 printk(KERN_ERR "Dirent at %08x has zeroes in name. Truncating to %d chars\n", 1033 ofs, checkedlen); 1034 } 1035 fd = jffs2_alloc_full_dirent(checkedlen+1); 1036 if (!fd) { 1037 return -ENOMEM; 1038 } 1039 memcpy(&fd->name, rd->name, checkedlen); 1040 fd->name[checkedlen] = 0; 1041 1042 crc = crc32(0, fd->name, rd->nsize); 1043 if (crc != je32_to_cpu(rd->name_crc)) { 1044 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1045 ofs, je32_to_cpu(rd->name_crc), crc); 1046 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino))); 1047 jffs2_free_full_dirent(fd); 1048 /* FIXME: Why do we believe totlen? */ 1049 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */ 1050 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen))))) 1051 return err; 1052 return 0; 1053 } 1054 ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino)); 1055 if (!ic) { 1056 jffs2_free_full_dirent(fd); 1057 return -ENOMEM; 1058 } 1059 1060 fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd), 1061 PAD(je32_to_cpu(rd->totlen)), ic); 1062 1063 fd->next = NULL; 1064 fd->version = je32_to_cpu(rd->version); 1065 fd->ino = je32_to_cpu(rd->ino); 1066 fd->nhash = full_name_hash(fd->name, checkedlen); 1067 fd->type = rd->type; 1068 jffs2_add_fd_to_list(c, fd, &ic->scan_dents); 1069 1070 if (jffs2_sum_active()) { 1071 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset); 1072 } 1073 1074 return 0; 1075 } 1076 1077 static int count_list(struct list_head *l) 1078 { 1079 uint32_t count = 0; 1080 struct list_head *tmp; 1081 1082 list_for_each(tmp, l) { 1083 count++; 1084 } 1085 return count; 1086 } 1087 1088 /* Note: This breaks if list_empty(head). I don't care. You 1089 might, if you copy this code and use it elsewhere :) */ 1090 static void rotate_list(struct list_head *head, uint32_t count) 1091 { 1092 struct list_head *n = head->next; 1093 1094 list_del(head); 1095 while(count--) { 1096 n = n->next; 1097 } 1098 list_add(head, n); 1099 } 1100 1101 void jffs2_rotate_lists(struct jffs2_sb_info *c) 1102 { 1103 uint32_t x; 1104 uint32_t rotateby; 1105 1106 x = count_list(&c->clean_list); 1107 if (x) { 1108 rotateby = pseudo_random % x; 1109 rotate_list((&c->clean_list), rotateby); 1110 } 1111 1112 x = count_list(&c->very_dirty_list); 1113 if (x) { 1114 rotateby = pseudo_random % x; 1115 rotate_list((&c->very_dirty_list), rotateby); 1116 } 1117 1118 x = count_list(&c->dirty_list); 1119 if (x) { 1120 rotateby = pseudo_random % x; 1121 rotate_list((&c->dirty_list), rotateby); 1122 } 1123 1124 x = count_list(&c->erasable_list); 1125 if (x) { 1126 rotateby = pseudo_random % x; 1127 rotate_list((&c->erasable_list), rotateby); 1128 } 1129 1130 if (c->nr_erasing_blocks) { 1131 rotateby = pseudo_random % c->nr_erasing_blocks; 1132 rotate_list((&c->erase_pending_list), rotateby); 1133 } 1134 1135 if (c->nr_free_blocks) { 1136 rotateby = pseudo_random % c->nr_free_blocks; 1137 rotate_list((&c->free_list), rotateby); 1138 } 1139 } 1140