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 ret = mtd_point(c->mtd, 0, c->mtd->size, &pointlen, 100 (void **)&flashbuf, NULL); 101 if (!ret && pointlen < c->mtd->size) { 102 /* Don't muck about if it won't let us point to the whole flash */ 103 jffs2_dbg(1, "MTD point returned len too short: 0x%zx\n", 104 pointlen); 105 mtd_unpoint(c->mtd, 0, pointlen); 106 flashbuf = NULL; 107 } 108 if (ret && ret != -EOPNOTSUPP) 109 jffs2_dbg(1, "MTD point failed %d\n", ret); 110 #endif 111 if (!flashbuf) { 112 /* For NAND it's quicker to read a whole eraseblock at a time, 113 apparently */ 114 if (jffs2_cleanmarker_oob(c)) 115 try_size = c->sector_size; 116 else 117 try_size = PAGE_SIZE; 118 119 jffs2_dbg(1, "Trying to allocate readbuf of %zu " 120 "bytes\n", try_size); 121 122 flashbuf = mtd_kmalloc_up_to(c->mtd, &try_size); 123 if (!flashbuf) 124 return -ENOMEM; 125 126 jffs2_dbg(1, "Allocated readbuf of %zu bytes\n", 127 try_size); 128 129 buf_size = (uint32_t)try_size; 130 } 131 132 if (jffs2_sum_active()) { 133 s = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL); 134 if (!s) { 135 JFFS2_WARNING("Can't allocate memory for summary\n"); 136 ret = -ENOMEM; 137 goto out; 138 } 139 } 140 141 for (i=0; i<c->nr_blocks; i++) { 142 struct jffs2_eraseblock *jeb = &c->blocks[i]; 143 144 cond_resched(); 145 146 /* reset summary info for next eraseblock scan */ 147 jffs2_sum_reset_collected(s); 148 149 ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset), 150 buf_size, s); 151 152 if (ret < 0) 153 goto out; 154 155 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 156 157 /* Now decide which list to put it on */ 158 switch(ret) { 159 case BLK_STATE_ALLFF: 160 /* 161 * Empty block. Since we can't be sure it 162 * was entirely erased, we just queue it for erase 163 * again. It will be marked as such when the erase 164 * is complete. Meanwhile we still count it as empty 165 * for later checks. 166 */ 167 empty_blocks++; 168 list_add(&jeb->list, &c->erase_pending_list); 169 c->nr_erasing_blocks++; 170 break; 171 172 case BLK_STATE_CLEANMARKER: 173 /* Only a CLEANMARKER node is valid */ 174 if (!jeb->dirty_size) { 175 /* It's actually free */ 176 list_add(&jeb->list, &c->free_list); 177 c->nr_free_blocks++; 178 } else { 179 /* Dirt */ 180 jffs2_dbg(1, "Adding all-dirty block at 0x%08x to erase_pending_list\n", 181 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 jffs2_dbg(1, "%s(): new nextblock = 0x%08x\n", 209 __func__, jeb->offset); 210 c->nextblock = jeb; 211 } else { 212 ret = file_dirty(c, jeb); 213 if (ret) 214 goto out; 215 } 216 break; 217 218 case BLK_STATE_ALLDIRTY: 219 /* Nothing valid - not even a clean marker. Needs erasing. */ 220 /* For now we just put it on the erasing list. We'll start the erases later */ 221 jffs2_dbg(1, "JFFS2: Erase block at 0x%08x is not formatted. It will be erased\n", 222 jeb->offset); 223 list_add(&jeb->list, &c->erase_pending_list); 224 c->nr_erasing_blocks++; 225 break; 226 227 case BLK_STATE_BADBLOCK: 228 jffs2_dbg(1, "JFFS2: Block at 0x%08x is bad\n", 229 jeb->offset); 230 list_add(&jeb->list, &c->bad_list); 231 c->bad_size += c->sector_size; 232 c->free_size -= c->sector_size; 233 bad_blocks++; 234 break; 235 default: 236 printk(KERN_WARNING "jffs2_scan_medium(): unknown block state\n"); 237 BUG(); 238 } 239 } 240 241 /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */ 242 if (c->nextblock && (c->nextblock->dirty_size)) { 243 c->nextblock->wasted_size += c->nextblock->dirty_size; 244 c->wasted_size += c->nextblock->dirty_size; 245 c->dirty_size -= c->nextblock->dirty_size; 246 c->nextblock->dirty_size = 0; 247 } 248 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 249 if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) { 250 /* If we're going to start writing into a block which already 251 contains data, and the end of the data isn't page-aligned, 252 skip a little and align it. */ 253 254 uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize; 255 256 jffs2_dbg(1, "%s(): Skipping %d bytes in nextblock to ensure page alignment\n", 257 __func__, skip); 258 jffs2_prealloc_raw_node_refs(c, c->nextblock, 1); 259 jffs2_scan_dirty_space(c, c->nextblock, skip); 260 } 261 #endif 262 if (c->nr_erasing_blocks) { 263 if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) { 264 printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n"); 265 printk(KERN_NOTICE "empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",empty_blocks,bad_blocks,c->nr_blocks); 266 ret = -EIO; 267 goto out; 268 } 269 spin_lock(&c->erase_completion_lock); 270 jffs2_garbage_collect_trigger(c); 271 spin_unlock(&c->erase_completion_lock); 272 } 273 ret = 0; 274 out: 275 if (buf_size) 276 kfree(flashbuf); 277 #ifndef __ECOS 278 else 279 mtd_unpoint(c->mtd, 0, c->mtd->size); 280 #endif 281 kfree(s); 282 return ret; 283 } 284 285 static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf, 286 uint32_t ofs, uint32_t len) 287 { 288 int ret; 289 size_t retlen; 290 291 ret = jffs2_flash_read(c, ofs, len, &retlen, buf); 292 if (ret) { 293 jffs2_dbg(1, "mtd->read(0x%x bytes from 0x%x) returned %d\n", 294 len, ofs, ret); 295 return ret; 296 } 297 if (retlen < len) { 298 jffs2_dbg(1, "Read at 0x%x gave only 0x%zx bytes\n", 299 ofs, retlen); 300 return -EIO; 301 } 302 return 0; 303 } 304 305 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb) 306 { 307 if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size 308 && (!jeb->first_node || !ref_next(jeb->first_node)) ) 309 return BLK_STATE_CLEANMARKER; 310 311 /* move blocks with max 4 byte dirty space to cleanlist */ 312 else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) { 313 c->dirty_size -= jeb->dirty_size; 314 c->wasted_size += jeb->dirty_size; 315 jeb->wasted_size += jeb->dirty_size; 316 jeb->dirty_size = 0; 317 return BLK_STATE_CLEAN; 318 } else if (jeb->used_size || jeb->unchecked_size) 319 return BLK_STATE_PARTDIRTY; 320 else 321 return BLK_STATE_ALLDIRTY; 322 } 323 324 #ifdef CONFIG_JFFS2_FS_XATTR 325 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 326 struct jffs2_raw_xattr *rx, uint32_t ofs, 327 struct jffs2_summary *s) 328 { 329 struct jffs2_xattr_datum *xd; 330 uint32_t xid, version, totlen, crc; 331 int err; 332 333 crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4); 334 if (crc != je32_to_cpu(rx->node_crc)) { 335 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n", 336 ofs, je32_to_cpu(rx->node_crc), crc); 337 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen)))) 338 return err; 339 return 0; 340 } 341 342 xid = je32_to_cpu(rx->xid); 343 version = je32_to_cpu(rx->version); 344 345 totlen = PAD(sizeof(struct jffs2_raw_xattr) 346 + rx->name_len + 1 + je16_to_cpu(rx->value_len)); 347 if (totlen != je32_to_cpu(rx->totlen)) { 348 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n", 349 ofs, je32_to_cpu(rx->totlen), totlen); 350 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen)))) 351 return err; 352 return 0; 353 } 354 355 xd = jffs2_setup_xattr_datum(c, xid, version); 356 if (IS_ERR(xd)) 357 return PTR_ERR(xd); 358 359 if (xd->version > version) { 360 struct jffs2_raw_node_ref *raw 361 = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL); 362 raw->next_in_ino = xd->node->next_in_ino; 363 xd->node->next_in_ino = raw; 364 } else { 365 xd->version = version; 366 xd->xprefix = rx->xprefix; 367 xd->name_len = rx->name_len; 368 xd->value_len = je16_to_cpu(rx->value_len); 369 xd->data_crc = je32_to_cpu(rx->data_crc); 370 371 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd); 372 } 373 374 if (jffs2_sum_active()) 375 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset); 376 dbg_xattr("scanning xdatum at %#08x (xid=%u, version=%u)\n", 377 ofs, xd->xid, xd->version); 378 return 0; 379 } 380 381 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 382 struct jffs2_raw_xref *rr, uint32_t ofs, 383 struct jffs2_summary *s) 384 { 385 struct jffs2_xattr_ref *ref; 386 uint32_t crc; 387 int err; 388 389 crc = crc32(0, rr, sizeof(*rr) - 4); 390 if (crc != je32_to_cpu(rr->node_crc)) { 391 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n", 392 ofs, je32_to_cpu(rr->node_crc), crc); 393 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen))))) 394 return err; 395 return 0; 396 } 397 398 if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) { 399 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n", 400 ofs, je32_to_cpu(rr->totlen), 401 PAD(sizeof(struct jffs2_raw_xref))); 402 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen)))) 403 return err; 404 return 0; 405 } 406 407 ref = jffs2_alloc_xattr_ref(); 408 if (!ref) 409 return -ENOMEM; 410 411 /* BEFORE jffs2_build_xattr_subsystem() called, 412 * and AFTER xattr_ref is marked as a dead xref, 413 * ref->xid is used to store 32bit xid, xd is not used 414 * ref->ino is used to store 32bit inode-number, ic is not used 415 * Thoes variables are declared as union, thus using those 416 * are exclusive. In a similar way, ref->next is temporarily 417 * used to chain all xattr_ref object. It's re-chained to 418 * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly. 419 */ 420 ref->ino = je32_to_cpu(rr->ino); 421 ref->xid = je32_to_cpu(rr->xid); 422 ref->xseqno = je32_to_cpu(rr->xseqno); 423 if (ref->xseqno > c->highest_xseqno) 424 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER); 425 ref->next = c->xref_temp; 426 c->xref_temp = ref; 427 428 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref); 429 430 if (jffs2_sum_active()) 431 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset); 432 dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n", 433 ofs, ref->xid, ref->ino); 434 return 0; 435 } 436 #endif 437 438 /* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into 439 the flash, XIP-style */ 440 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 441 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) { 442 struct jffs2_unknown_node *node; 443 struct jffs2_unknown_node crcnode; 444 uint32_t ofs, prevofs, max_ofs; 445 uint32_t hdr_crc, buf_ofs, buf_len; 446 int err; 447 int noise = 0; 448 449 450 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 451 int cleanmarkerfound = 0; 452 #endif 453 454 ofs = jeb->offset; 455 prevofs = jeb->offset - 1; 456 457 jffs2_dbg(1, "%s(): Scanning block at 0x%x\n", __func__, ofs); 458 459 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 460 if (jffs2_cleanmarker_oob(c)) { 461 int ret; 462 463 if (mtd_block_isbad(c->mtd, jeb->offset)) 464 return BLK_STATE_BADBLOCK; 465 466 ret = jffs2_check_nand_cleanmarker(c, jeb); 467 jffs2_dbg(2, "jffs_check_nand_cleanmarker returned %d\n", ret); 468 469 /* Even if it's not found, we still scan to see 470 if the block is empty. We use this information 471 to decide whether to erase it or not. */ 472 switch (ret) { 473 case 0: cleanmarkerfound = 1; break; 474 case 1: break; 475 default: return ret; 476 } 477 } 478 #endif 479 480 if (jffs2_sum_active()) { 481 struct jffs2_sum_marker *sm; 482 void *sumptr = NULL; 483 uint32_t sumlen; 484 485 if (!buf_size) { 486 /* XIP case. Just look, point at the summary if it's there */ 487 sm = (void *)buf + c->sector_size - sizeof(*sm); 488 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) { 489 sumptr = buf + je32_to_cpu(sm->offset); 490 sumlen = c->sector_size - je32_to_cpu(sm->offset); 491 } 492 } else { 493 /* If NAND flash, read a whole page of it. Else just the end */ 494 if (c->wbuf_pagesize) 495 buf_len = c->wbuf_pagesize; 496 else 497 buf_len = sizeof(*sm); 498 499 /* Read as much as we want into the _end_ of the preallocated buffer */ 500 err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, 501 jeb->offset + c->sector_size - buf_len, 502 buf_len); 503 if (err) 504 return err; 505 506 sm = (void *)buf + buf_size - sizeof(*sm); 507 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) { 508 sumlen = c->sector_size - je32_to_cpu(sm->offset); 509 sumptr = buf + buf_size - sumlen; 510 511 /* Now, make sure the summary itself is available */ 512 if (sumlen > buf_size) { 513 /* Need to kmalloc for this. */ 514 sumptr = kmalloc(sumlen, GFP_KERNEL); 515 if (!sumptr) 516 return -ENOMEM; 517 memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len); 518 } 519 if (buf_len < sumlen) { 520 /* Need to read more so that the entire summary node is present */ 521 err = jffs2_fill_scan_buf(c, sumptr, 522 jeb->offset + c->sector_size - sumlen, 523 sumlen - buf_len); 524 if (err) 525 return err; 526 } 527 } 528 529 } 530 531 if (sumptr) { 532 err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random); 533 534 if (buf_size && sumlen > buf_size) 535 kfree(sumptr); 536 /* If it returns with a real error, bail. 537 If it returns positive, that's a block classification 538 (i.e. BLK_STATE_xxx) so return that too. 539 If it returns zero, fall through to full scan. */ 540 if (err) 541 return err; 542 } 543 } 544 545 buf_ofs = jeb->offset; 546 547 if (!buf_size) { 548 /* This is the XIP case -- we're reading _directly_ from the flash chip */ 549 buf_len = c->sector_size; 550 } else { 551 buf_len = EMPTY_SCAN_SIZE(c->sector_size); 552 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len); 553 if (err) 554 return err; 555 } 556 557 /* We temporarily use 'ofs' as a pointer into the buffer/jeb */ 558 ofs = 0; 559 max_ofs = EMPTY_SCAN_SIZE(c->sector_size); 560 /* Scan only EMPTY_SCAN_SIZE of 0xFF before declaring it's empty */ 561 while(ofs < max_ofs && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF) 562 ofs += 4; 563 564 if (ofs == max_ofs) { 565 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 566 if (jffs2_cleanmarker_oob(c)) { 567 /* scan oob, take care of cleanmarker */ 568 int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound); 569 jffs2_dbg(2, "jffs2_check_oob_empty returned %d\n", 570 ret); 571 switch (ret) { 572 case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF; 573 case 1: return BLK_STATE_ALLDIRTY; 574 default: return ret; 575 } 576 } 577 #endif 578 jffs2_dbg(1, "Block at 0x%08x is empty (erased)\n", 579 jeb->offset); 580 if (c->cleanmarker_size == 0) 581 return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */ 582 else 583 return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */ 584 } 585 if (ofs) { 586 jffs2_dbg(1, "Free space at %08x ends at %08x\n", jeb->offset, 587 jeb->offset + ofs); 588 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1))) 589 return err; 590 if ((err = jffs2_scan_dirty_space(c, jeb, ofs))) 591 return err; 592 } 593 594 /* Now ofs is a complete physical flash offset as it always was... */ 595 ofs += jeb->offset; 596 597 noise = 10; 598 599 dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset); 600 601 scan_more: 602 while(ofs < jeb->offset + c->sector_size) { 603 604 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 605 606 /* Make sure there are node refs available for use */ 607 err = jffs2_prealloc_raw_node_refs(c, jeb, 2); 608 if (err) 609 return err; 610 611 cond_resched(); 612 613 if (ofs & 3) { 614 printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs); 615 ofs = PAD(ofs); 616 continue; 617 } 618 if (ofs == prevofs) { 619 printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs); 620 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 621 return err; 622 ofs += 4; 623 continue; 624 } 625 prevofs = ofs; 626 627 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) { 628 jffs2_dbg(1, "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n", 629 sizeof(struct jffs2_unknown_node), 630 jeb->offset, c->sector_size, ofs, 631 sizeof(*node)); 632 if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs))) 633 return err; 634 break; 635 } 636 637 if (buf_ofs + buf_len < ofs + sizeof(*node)) { 638 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 639 jffs2_dbg(1, "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n", 640 sizeof(struct jffs2_unknown_node), 641 buf_len, ofs); 642 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 643 if (err) 644 return err; 645 buf_ofs = ofs; 646 } 647 648 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs]; 649 650 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) { 651 uint32_t inbuf_ofs; 652 uint32_t empty_start, scan_end; 653 654 empty_start = ofs; 655 ofs += 4; 656 scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len); 657 658 jffs2_dbg(1, "Found empty flash at 0x%08x\n", ofs); 659 more_empty: 660 inbuf_ofs = ofs - buf_ofs; 661 while (inbuf_ofs < scan_end) { 662 if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) { 663 printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n", 664 empty_start, ofs); 665 if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start))) 666 return err; 667 goto scan_more; 668 } 669 670 inbuf_ofs+=4; 671 ofs += 4; 672 } 673 /* Ran off end. */ 674 jffs2_dbg(1, "Empty flash to end of buffer at 0x%08x\n", 675 ofs); 676 677 /* If we're only checking the beginning of a block with a cleanmarker, 678 bail now */ 679 if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) && 680 c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) { 681 jffs2_dbg(1, "%d bytes at start of block seems clean... assuming all clean\n", 682 EMPTY_SCAN_SIZE(c->sector_size)); 683 return BLK_STATE_CLEANMARKER; 684 } 685 if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */ 686 scan_end = buf_len; 687 goto more_empty; 688 } 689 690 /* See how much more there is to read in this eraseblock... */ 691 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 692 if (!buf_len) { 693 /* No more to read. Break out of main loop without marking 694 this range of empty space as dirty (because it's not) */ 695 jffs2_dbg(1, "Empty flash at %08x runs to end of block. Treating as free_space\n", 696 empty_start); 697 break; 698 } 699 /* point never reaches here */ 700 scan_end = buf_len; 701 jffs2_dbg(1, "Reading another 0x%x at 0x%08x\n", 702 buf_len, ofs); 703 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 704 if (err) 705 return err; 706 buf_ofs = ofs; 707 goto more_empty; 708 } 709 710 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) { 711 printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs); 712 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 713 return err; 714 ofs += 4; 715 continue; 716 } 717 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) { 718 jffs2_dbg(1, "Dirty bitmask at 0x%08x\n", ofs); 719 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 720 return err; 721 ofs += 4; 722 continue; 723 } 724 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) { 725 printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs); 726 printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n"); 727 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 728 return err; 729 ofs += 4; 730 continue; 731 } 732 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) { 733 /* OK. We're out of possibilities. Whinge and move on */ 734 noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n", 735 JFFS2_MAGIC_BITMASK, ofs, 736 je16_to_cpu(node->magic)); 737 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 738 return err; 739 ofs += 4; 740 continue; 741 } 742 /* We seem to have a node of sorts. Check the CRC */ 743 crcnode.magic = node->magic; 744 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE); 745 crcnode.totlen = node->totlen; 746 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4); 747 748 if (hdr_crc != je32_to_cpu(node->hdr_crc)) { 749 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", 750 ofs, je16_to_cpu(node->magic), 751 je16_to_cpu(node->nodetype), 752 je32_to_cpu(node->totlen), 753 je32_to_cpu(node->hdr_crc), 754 hdr_crc); 755 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 756 return err; 757 ofs += 4; 758 continue; 759 } 760 761 if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) { 762 /* Eep. Node goes over the end of the erase block. */ 763 printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n", 764 ofs, je32_to_cpu(node->totlen)); 765 printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n"); 766 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 767 return err; 768 ofs += 4; 769 continue; 770 } 771 772 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) { 773 /* Wheee. This is an obsoleted node */ 774 jffs2_dbg(2, "Node at 0x%08x is obsolete. Skipping\n", 775 ofs); 776 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 777 return err; 778 ofs += PAD(je32_to_cpu(node->totlen)); 779 continue; 780 } 781 782 switch(je16_to_cpu(node->nodetype)) { 783 case JFFS2_NODETYPE_INODE: 784 if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) { 785 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 786 jffs2_dbg(1, "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n", 787 sizeof(struct jffs2_raw_inode), 788 buf_len, ofs); 789 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 790 if (err) 791 return err; 792 buf_ofs = ofs; 793 node = (void *)buf; 794 } 795 err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s); 796 if (err) return err; 797 ofs += PAD(je32_to_cpu(node->totlen)); 798 break; 799 800 case JFFS2_NODETYPE_DIRENT: 801 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 802 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 803 jffs2_dbg(1, "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n", 804 je32_to_cpu(node->totlen), buf_len, 805 ofs); 806 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 807 if (err) 808 return err; 809 buf_ofs = ofs; 810 node = (void *)buf; 811 } 812 err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s); 813 if (err) return err; 814 ofs += PAD(je32_to_cpu(node->totlen)); 815 break; 816 817 #ifdef CONFIG_JFFS2_FS_XATTR 818 case JFFS2_NODETYPE_XATTR: 819 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 820 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 821 jffs2_dbg(1, "Fewer than %d bytes (xattr node) left to end of buf. Reading 0x%x at 0x%08x\n", 822 je32_to_cpu(node->totlen), buf_len, 823 ofs); 824 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 825 if (err) 826 return err; 827 buf_ofs = ofs; 828 node = (void *)buf; 829 } 830 err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s); 831 if (err) 832 return err; 833 ofs += PAD(je32_to_cpu(node->totlen)); 834 break; 835 case JFFS2_NODETYPE_XREF: 836 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 837 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 838 jffs2_dbg(1, "Fewer than %d bytes (xref node) left to end of buf. Reading 0x%x at 0x%08x\n", 839 je32_to_cpu(node->totlen), buf_len, 840 ofs); 841 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 842 if (err) 843 return err; 844 buf_ofs = ofs; 845 node = (void *)buf; 846 } 847 err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s); 848 if (err) 849 return err; 850 ofs += PAD(je32_to_cpu(node->totlen)); 851 break; 852 #endif /* CONFIG_JFFS2_FS_XATTR */ 853 854 case JFFS2_NODETYPE_CLEANMARKER: 855 jffs2_dbg(1, "CLEANMARKER node found at 0x%08x\n", ofs); 856 if (je32_to_cpu(node->totlen) != c->cleanmarker_size) { 857 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n", 858 ofs, je32_to_cpu(node->totlen), c->cleanmarker_size); 859 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node))))) 860 return err; 861 ofs += PAD(sizeof(struct jffs2_unknown_node)); 862 } else if (jeb->first_node) { 863 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset); 864 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node))))) 865 return err; 866 ofs += PAD(sizeof(struct jffs2_unknown_node)); 867 } else { 868 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL); 869 870 ofs += PAD(c->cleanmarker_size); 871 } 872 break; 873 874 case JFFS2_NODETYPE_PADDING: 875 if (jffs2_sum_active()) 876 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen)); 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 default: 883 switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) { 884 case JFFS2_FEATURE_ROCOMPAT: 885 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs); 886 c->flags |= JFFS2_SB_FLAG_RO; 887 if (!(jffs2_is_readonly(c))) 888 return -EROFS; 889 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 890 return err; 891 ofs += PAD(je32_to_cpu(node->totlen)); 892 break; 893 894 case JFFS2_FEATURE_INCOMPAT: 895 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs); 896 return -EINVAL; 897 898 case JFFS2_FEATURE_RWCOMPAT_DELETE: 899 jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", 900 je16_to_cpu(node->nodetype), ofs); 901 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 902 return err; 903 ofs += PAD(je32_to_cpu(node->totlen)); 904 break; 905 906 case JFFS2_FEATURE_RWCOMPAT_COPY: { 907 jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", 908 je16_to_cpu(node->nodetype), ofs); 909 910 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL); 911 912 /* We can't summarise nodes we don't grok */ 913 jffs2_sum_disable_collecting(s); 914 ofs += PAD(je32_to_cpu(node->totlen)); 915 break; 916 } 917 } 918 } 919 } 920 921 if (jffs2_sum_active()) { 922 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) { 923 dbg_summary("There is not enough space for " 924 "summary information, disabling for this jeb!\n"); 925 jffs2_sum_disable_collecting(s); 926 } 927 } 928 929 jffs2_dbg(1, "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n", 930 jeb->offset, jeb->free_size, jeb->dirty_size, 931 jeb->unchecked_size, jeb->used_size, jeb->wasted_size); 932 933 /* mark_node_obsolete can add to wasted !! */ 934 if (jeb->wasted_size) { 935 jeb->dirty_size += jeb->wasted_size; 936 c->dirty_size += jeb->wasted_size; 937 c->wasted_size -= jeb->wasted_size; 938 jeb->wasted_size = 0; 939 } 940 941 return jffs2_scan_classify_jeb(c, jeb); 942 } 943 944 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino) 945 { 946 struct jffs2_inode_cache *ic; 947 948 ic = jffs2_get_ino_cache(c, ino); 949 if (ic) 950 return ic; 951 952 if (ino > c->highest_ino) 953 c->highest_ino = ino; 954 955 ic = jffs2_alloc_inode_cache(); 956 if (!ic) { 957 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n"); 958 return NULL; 959 } 960 memset(ic, 0, sizeof(*ic)); 961 962 ic->ino = ino; 963 ic->nodes = (void *)ic; 964 jffs2_add_ino_cache(c, ic); 965 if (ino == 1) 966 ic->pino_nlink = 1; 967 return ic; 968 } 969 970 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 971 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s) 972 { 973 struct jffs2_inode_cache *ic; 974 uint32_t crc, ino = je32_to_cpu(ri->ino); 975 976 jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs); 977 978 /* We do very little here now. Just check the ino# to which we should attribute 979 this node; we can do all the CRC checking etc. later. There's a tradeoff here -- 980 we used to scan the flash once only, reading everything we want from it into 981 memory, then building all our in-core data structures and freeing the extra 982 information. Now we allow the first part of the mount to complete a lot quicker, 983 but we have to go _back_ to the flash in order to finish the CRC checking, etc. 984 Which means that the _full_ amount of time to get to proper write mode with GC 985 operational may actually be _longer_ than before. Sucks to be me. */ 986 987 /* Check the node CRC in any case. */ 988 crc = crc32(0, ri, sizeof(*ri)-8); 989 if (crc != je32_to_cpu(ri->node_crc)) { 990 printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on " 991 "node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 992 ofs, je32_to_cpu(ri->node_crc), crc); 993 /* 994 * We believe totlen because the CRC on the node 995 * _header_ was OK, just the node itself failed. 996 */ 997 return jffs2_scan_dirty_space(c, jeb, 998 PAD(je32_to_cpu(ri->totlen))); 999 } 1000 1001 ic = jffs2_get_ino_cache(c, ino); 1002 if (!ic) { 1003 ic = jffs2_scan_make_ino_cache(c, ino); 1004 if (!ic) 1005 return -ENOMEM; 1006 } 1007 1008 /* Wheee. It worked */ 1009 jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic); 1010 1011 jffs2_dbg(1, "Node is ino #%u, version %d. Range 0x%x-0x%x\n", 1012 je32_to_cpu(ri->ino), je32_to_cpu(ri->version), 1013 je32_to_cpu(ri->offset), 1014 je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)); 1015 1016 pseudo_random += je32_to_cpu(ri->version); 1017 1018 if (jffs2_sum_active()) { 1019 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset); 1020 } 1021 1022 return 0; 1023 } 1024 1025 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 1026 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s) 1027 { 1028 struct jffs2_full_dirent *fd; 1029 struct jffs2_inode_cache *ic; 1030 uint32_t checkedlen; 1031 uint32_t crc; 1032 int err; 1033 1034 jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs); 1035 1036 /* We don't get here unless the node is still valid, so we don't have to 1037 mask in the ACCURATE bit any more. */ 1038 crc = crc32(0, rd, sizeof(*rd)-8); 1039 1040 if (crc != je32_to_cpu(rd->node_crc)) { 1041 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1042 ofs, je32_to_cpu(rd->node_crc), crc); 1043 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */ 1044 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen))))) 1045 return err; 1046 return 0; 1047 } 1048 1049 pseudo_random += je32_to_cpu(rd->version); 1050 1051 /* Should never happen. Did. (OLPC trac #4184)*/ 1052 checkedlen = strnlen(rd->name, rd->nsize); 1053 if (checkedlen < rd->nsize) { 1054 printk(KERN_ERR "Dirent at %08x has zeroes in name. Truncating to %d chars\n", 1055 ofs, checkedlen); 1056 } 1057 fd = jffs2_alloc_full_dirent(checkedlen+1); 1058 if (!fd) { 1059 return -ENOMEM; 1060 } 1061 memcpy(&fd->name, rd->name, checkedlen); 1062 fd->name[checkedlen] = 0; 1063 1064 crc = crc32(0, fd->name, rd->nsize); 1065 if (crc != je32_to_cpu(rd->name_crc)) { 1066 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1067 ofs, je32_to_cpu(rd->name_crc), crc); 1068 jffs2_dbg(1, "Name for which CRC failed is (now) '%s', ino #%d\n", 1069 fd->name, je32_to_cpu(rd->ino)); 1070 jffs2_free_full_dirent(fd); 1071 /* FIXME: Why do we believe totlen? */ 1072 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */ 1073 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen))))) 1074 return err; 1075 return 0; 1076 } 1077 ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino)); 1078 if (!ic) { 1079 jffs2_free_full_dirent(fd); 1080 return -ENOMEM; 1081 } 1082 1083 fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd), 1084 PAD(je32_to_cpu(rd->totlen)), ic); 1085 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, checkedlen); 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 } 1163