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, fmt, ...) \ 26 do { \ 27 if (*(noise)) { \ 28 pr_notice(fmt, ##__VA_ARGS__); \ 29 (*(noise))--; \ 30 if (!(*(noise))) \ 31 pr_notice("Further such events for this erase block will not be printed\n"); \ 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 pr_warn("%s(): unknown block state\n", __func__); 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 pr_notice("Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n"); 265 pr_notice("empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n", 266 empty_blocks, bad_blocks, c->nr_blocks); 267 ret = -EIO; 268 goto out; 269 } 270 spin_lock(&c->erase_completion_lock); 271 jffs2_garbage_collect_trigger(c); 272 spin_unlock(&c->erase_completion_lock); 273 } 274 ret = 0; 275 out: 276 if (buf_size) 277 kfree(flashbuf); 278 #ifndef __ECOS 279 else 280 mtd_unpoint(c->mtd, 0, c->mtd->size); 281 #endif 282 kfree(s); 283 return ret; 284 } 285 286 static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf, 287 uint32_t ofs, uint32_t len) 288 { 289 int ret; 290 size_t retlen; 291 292 ret = jffs2_flash_read(c, ofs, len, &retlen, buf); 293 if (ret) { 294 jffs2_dbg(1, "mtd->read(0x%x bytes from 0x%x) returned %d\n", 295 len, ofs, ret); 296 return ret; 297 } 298 if (retlen < len) { 299 jffs2_dbg(1, "Read at 0x%x gave only 0x%zx bytes\n", 300 ofs, retlen); 301 return -EIO; 302 } 303 return 0; 304 } 305 306 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb) 307 { 308 if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size 309 && (!jeb->first_node || !ref_next(jeb->first_node)) ) 310 return BLK_STATE_CLEANMARKER; 311 312 /* move blocks with max 4 byte dirty space to cleanlist */ 313 else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) { 314 c->dirty_size -= jeb->dirty_size; 315 c->wasted_size += jeb->dirty_size; 316 jeb->wasted_size += jeb->dirty_size; 317 jeb->dirty_size = 0; 318 return BLK_STATE_CLEAN; 319 } else if (jeb->used_size || jeb->unchecked_size) 320 return BLK_STATE_PARTDIRTY; 321 else 322 return BLK_STATE_ALLDIRTY; 323 } 324 325 #ifdef CONFIG_JFFS2_FS_XATTR 326 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 327 struct jffs2_raw_xattr *rx, uint32_t ofs, 328 struct jffs2_summary *s) 329 { 330 struct jffs2_xattr_datum *xd; 331 uint32_t xid, version, totlen, crc; 332 int err; 333 334 crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4); 335 if (crc != je32_to_cpu(rx->node_crc)) { 336 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n", 337 ofs, je32_to_cpu(rx->node_crc), crc); 338 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen)))) 339 return err; 340 return 0; 341 } 342 343 xid = je32_to_cpu(rx->xid); 344 version = je32_to_cpu(rx->version); 345 346 totlen = PAD(sizeof(struct jffs2_raw_xattr) 347 + rx->name_len + 1 + je16_to_cpu(rx->value_len)); 348 if (totlen != je32_to_cpu(rx->totlen)) { 349 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n", 350 ofs, je32_to_cpu(rx->totlen), totlen); 351 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen)))) 352 return err; 353 return 0; 354 } 355 356 xd = jffs2_setup_xattr_datum(c, xid, version); 357 if (IS_ERR(xd)) 358 return PTR_ERR(xd); 359 360 if (xd->version > version) { 361 struct jffs2_raw_node_ref *raw 362 = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL); 363 raw->next_in_ino = xd->node->next_in_ino; 364 xd->node->next_in_ino = raw; 365 } else { 366 xd->version = version; 367 xd->xprefix = rx->xprefix; 368 xd->name_len = rx->name_len; 369 xd->value_len = je16_to_cpu(rx->value_len); 370 xd->data_crc = je32_to_cpu(rx->data_crc); 371 372 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd); 373 } 374 375 if (jffs2_sum_active()) 376 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset); 377 dbg_xattr("scanning xdatum at %#08x (xid=%u, version=%u)\n", 378 ofs, xd->xid, xd->version); 379 return 0; 380 } 381 382 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 383 struct jffs2_raw_xref *rr, uint32_t ofs, 384 struct jffs2_summary *s) 385 { 386 struct jffs2_xattr_ref *ref; 387 uint32_t crc; 388 int err; 389 390 crc = crc32(0, rr, sizeof(*rr) - 4); 391 if (crc != je32_to_cpu(rr->node_crc)) { 392 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n", 393 ofs, je32_to_cpu(rr->node_crc), crc); 394 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen))))) 395 return err; 396 return 0; 397 } 398 399 if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) { 400 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n", 401 ofs, je32_to_cpu(rr->totlen), 402 PAD(sizeof(struct jffs2_raw_xref))); 403 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen)))) 404 return err; 405 return 0; 406 } 407 408 ref = jffs2_alloc_xattr_ref(); 409 if (!ref) 410 return -ENOMEM; 411 412 /* BEFORE jffs2_build_xattr_subsystem() called, 413 * and AFTER xattr_ref is marked as a dead xref, 414 * ref->xid is used to store 32bit xid, xd is not used 415 * ref->ino is used to store 32bit inode-number, ic is not used 416 * Thoes variables are declared as union, thus using those 417 * are exclusive. In a similar way, ref->next is temporarily 418 * used to chain all xattr_ref object. It's re-chained to 419 * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly. 420 */ 421 ref->ino = je32_to_cpu(rr->ino); 422 ref->xid = je32_to_cpu(rr->xid); 423 ref->xseqno = je32_to_cpu(rr->xseqno); 424 if (ref->xseqno > c->highest_xseqno) 425 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER); 426 ref->next = c->xref_temp; 427 c->xref_temp = ref; 428 429 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref); 430 431 if (jffs2_sum_active()) 432 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset); 433 dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n", 434 ofs, ref->xid, ref->ino); 435 return 0; 436 } 437 #endif 438 439 /* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into 440 the flash, XIP-style */ 441 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 442 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) { 443 struct jffs2_unknown_node *node; 444 struct jffs2_unknown_node crcnode; 445 uint32_t ofs, prevofs, max_ofs; 446 uint32_t hdr_crc, buf_ofs, buf_len; 447 int err; 448 int noise = 0; 449 450 451 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 452 int cleanmarkerfound = 0; 453 #endif 454 455 ofs = jeb->offset; 456 prevofs = jeb->offset - 1; 457 458 jffs2_dbg(1, "%s(): Scanning block at 0x%x\n", __func__, ofs); 459 460 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 461 if (jffs2_cleanmarker_oob(c)) { 462 int ret; 463 464 if (mtd_block_isbad(c->mtd, jeb->offset)) 465 return BLK_STATE_BADBLOCK; 466 467 ret = jffs2_check_nand_cleanmarker(c, jeb); 468 jffs2_dbg(2, "jffs_check_nand_cleanmarker returned %d\n", ret); 469 470 /* Even if it's not found, we still scan to see 471 if the block is empty. We use this information 472 to decide whether to erase it or not. */ 473 switch (ret) { 474 case 0: cleanmarkerfound = 1; break; 475 case 1: break; 476 default: return ret; 477 } 478 } 479 #endif 480 481 if (jffs2_sum_active()) { 482 struct jffs2_sum_marker *sm; 483 void *sumptr = NULL; 484 uint32_t sumlen; 485 486 if (!buf_size) { 487 /* XIP case. Just look, point at the summary if it's there */ 488 sm = (void *)buf + c->sector_size - sizeof(*sm); 489 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) { 490 sumptr = buf + je32_to_cpu(sm->offset); 491 sumlen = c->sector_size - je32_to_cpu(sm->offset); 492 } 493 } else { 494 /* If NAND flash, read a whole page of it. Else just the end */ 495 if (c->wbuf_pagesize) 496 buf_len = c->wbuf_pagesize; 497 else 498 buf_len = sizeof(*sm); 499 500 /* Read as much as we want into the _end_ of the preallocated buffer */ 501 err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, 502 jeb->offset + c->sector_size - buf_len, 503 buf_len); 504 if (err) 505 return err; 506 507 sm = (void *)buf + buf_size - sizeof(*sm); 508 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) { 509 sumlen = c->sector_size - je32_to_cpu(sm->offset); 510 sumptr = buf + buf_size - sumlen; 511 512 /* Now, make sure the summary itself is available */ 513 if (sumlen > buf_size) { 514 /* Need to kmalloc for this. */ 515 sumptr = kmalloc(sumlen, GFP_KERNEL); 516 if (!sumptr) 517 return -ENOMEM; 518 memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len); 519 } 520 if (buf_len < sumlen) { 521 /* Need to read more so that the entire summary node is present */ 522 err = jffs2_fill_scan_buf(c, sumptr, 523 jeb->offset + c->sector_size - sumlen, 524 sumlen - buf_len); 525 if (err) 526 return err; 527 } 528 } 529 530 } 531 532 if (sumptr) { 533 err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random); 534 535 if (buf_size && sumlen > buf_size) 536 kfree(sumptr); 537 /* If it returns with a real error, bail. 538 If it returns positive, that's a block classification 539 (i.e. BLK_STATE_xxx) so return that too. 540 If it returns zero, fall through to full scan. */ 541 if (err) 542 return err; 543 } 544 } 545 546 buf_ofs = jeb->offset; 547 548 if (!buf_size) { 549 /* This is the XIP case -- we're reading _directly_ from the flash chip */ 550 buf_len = c->sector_size; 551 } else { 552 buf_len = EMPTY_SCAN_SIZE(c->sector_size); 553 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len); 554 if (err) 555 return err; 556 } 557 558 /* We temporarily use 'ofs' as a pointer into the buffer/jeb */ 559 ofs = 0; 560 max_ofs = EMPTY_SCAN_SIZE(c->sector_size); 561 /* Scan only EMPTY_SCAN_SIZE of 0xFF before declaring it's empty */ 562 while(ofs < max_ofs && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF) 563 ofs += 4; 564 565 if (ofs == max_ofs) { 566 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 567 if (jffs2_cleanmarker_oob(c)) { 568 /* scan oob, take care of cleanmarker */ 569 int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound); 570 jffs2_dbg(2, "jffs2_check_oob_empty returned %d\n", 571 ret); 572 switch (ret) { 573 case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF; 574 case 1: return BLK_STATE_ALLDIRTY; 575 default: return ret; 576 } 577 } 578 #endif 579 jffs2_dbg(1, "Block at 0x%08x is empty (erased)\n", 580 jeb->offset); 581 if (c->cleanmarker_size == 0) 582 return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */ 583 else 584 return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */ 585 } 586 if (ofs) { 587 jffs2_dbg(1, "Free space at %08x ends at %08x\n", jeb->offset, 588 jeb->offset + ofs); 589 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1))) 590 return err; 591 if ((err = jffs2_scan_dirty_space(c, jeb, ofs))) 592 return err; 593 } 594 595 /* Now ofs is a complete physical flash offset as it always was... */ 596 ofs += jeb->offset; 597 598 noise = 10; 599 600 dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset); 601 602 scan_more: 603 while(ofs < jeb->offset + c->sector_size) { 604 605 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 606 607 /* Make sure there are node refs available for use */ 608 err = jffs2_prealloc_raw_node_refs(c, jeb, 2); 609 if (err) 610 return err; 611 612 cond_resched(); 613 614 if (ofs & 3) { 615 pr_warn("Eep. ofs 0x%08x not word-aligned!\n", ofs); 616 ofs = PAD(ofs); 617 continue; 618 } 619 if (ofs == prevofs) { 620 pr_warn("ofs 0x%08x has already been seen. Skipping\n", 621 ofs); 622 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 623 return err; 624 ofs += 4; 625 continue; 626 } 627 prevofs = ofs; 628 629 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) { 630 jffs2_dbg(1, "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n", 631 sizeof(struct jffs2_unknown_node), 632 jeb->offset, c->sector_size, ofs, 633 sizeof(*node)); 634 if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs))) 635 return err; 636 break; 637 } 638 639 if (buf_ofs + buf_len < ofs + sizeof(*node)) { 640 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 641 jffs2_dbg(1, "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n", 642 sizeof(struct jffs2_unknown_node), 643 buf_len, ofs); 644 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 645 if (err) 646 return err; 647 buf_ofs = ofs; 648 } 649 650 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs]; 651 652 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) { 653 uint32_t inbuf_ofs; 654 uint32_t empty_start, scan_end; 655 656 empty_start = ofs; 657 ofs += 4; 658 scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len); 659 660 jffs2_dbg(1, "Found empty flash at 0x%08x\n", ofs); 661 more_empty: 662 inbuf_ofs = ofs - buf_ofs; 663 while (inbuf_ofs < scan_end) { 664 if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) { 665 pr_warn("Empty flash at 0x%08x ends at 0x%08x\n", 666 empty_start, ofs); 667 if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start))) 668 return err; 669 goto scan_more; 670 } 671 672 inbuf_ofs+=4; 673 ofs += 4; 674 } 675 /* Ran off end. */ 676 jffs2_dbg(1, "Empty flash to end of buffer at 0x%08x\n", 677 ofs); 678 679 /* If we're only checking the beginning of a block with a cleanmarker, 680 bail now */ 681 if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) && 682 c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) { 683 jffs2_dbg(1, "%d bytes at start of block seems clean... assuming all clean\n", 684 EMPTY_SCAN_SIZE(c->sector_size)); 685 return BLK_STATE_CLEANMARKER; 686 } 687 if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */ 688 scan_end = buf_len; 689 goto more_empty; 690 } 691 692 /* See how much more there is to read in this eraseblock... */ 693 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 694 if (!buf_len) { 695 /* No more to read. Break out of main loop without marking 696 this range of empty space as dirty (because it's not) */ 697 jffs2_dbg(1, "Empty flash at %08x runs to end of block. Treating as free_space\n", 698 empty_start); 699 break; 700 } 701 /* point never reaches here */ 702 scan_end = buf_len; 703 jffs2_dbg(1, "Reading another 0x%x at 0x%08x\n", 704 buf_len, ofs); 705 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 706 if (err) 707 return err; 708 buf_ofs = ofs; 709 goto more_empty; 710 } 711 712 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) { 713 pr_warn("Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", 714 ofs); 715 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 716 return err; 717 ofs += 4; 718 continue; 719 } 720 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) { 721 jffs2_dbg(1, "Dirty bitmask at 0x%08x\n", ofs); 722 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 723 return err; 724 ofs += 4; 725 continue; 726 } 727 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) { 728 pr_warn("Old JFFS2 bitmask found at 0x%08x\n", ofs); 729 pr_warn("You cannot use older JFFS2 filesystems with newer kernels\n"); 730 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 731 return err; 732 ofs += 4; 733 continue; 734 } 735 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) { 736 /* OK. We're out of possibilities. Whinge and move on */ 737 noisy_printk(&noise, "%s(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n", 738 __func__, 739 JFFS2_MAGIC_BITMASK, ofs, 740 je16_to_cpu(node->magic)); 741 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 742 return err; 743 ofs += 4; 744 continue; 745 } 746 /* We seem to have a node of sorts. Check the CRC */ 747 crcnode.magic = node->magic; 748 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE); 749 crcnode.totlen = node->totlen; 750 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4); 751 752 if (hdr_crc != je32_to_cpu(node->hdr_crc)) { 753 noisy_printk(&noise, "%s(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n", 754 __func__, 755 ofs, je16_to_cpu(node->magic), 756 je16_to_cpu(node->nodetype), 757 je32_to_cpu(node->totlen), 758 je32_to_cpu(node->hdr_crc), 759 hdr_crc); 760 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 761 return err; 762 ofs += 4; 763 continue; 764 } 765 766 if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) { 767 /* Eep. Node goes over the end of the erase block. */ 768 pr_warn("Node at 0x%08x with length 0x%08x would run over the end of the erase block\n", 769 ofs, je32_to_cpu(node->totlen)); 770 pr_warn("Perhaps the file system was created with the wrong erase size?\n"); 771 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 772 return err; 773 ofs += 4; 774 continue; 775 } 776 777 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) { 778 /* Wheee. This is an obsoleted node */ 779 jffs2_dbg(2, "Node at 0x%08x is obsolete. Skipping\n", 780 ofs); 781 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 782 return err; 783 ofs += PAD(je32_to_cpu(node->totlen)); 784 continue; 785 } 786 787 switch(je16_to_cpu(node->nodetype)) { 788 case JFFS2_NODETYPE_INODE: 789 if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) { 790 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 791 jffs2_dbg(1, "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n", 792 sizeof(struct jffs2_raw_inode), 793 buf_len, ofs); 794 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 795 if (err) 796 return err; 797 buf_ofs = ofs; 798 node = (void *)buf; 799 } 800 err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s); 801 if (err) return err; 802 ofs += PAD(je32_to_cpu(node->totlen)); 803 break; 804 805 case JFFS2_NODETYPE_DIRENT: 806 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 807 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 808 jffs2_dbg(1, "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n", 809 je32_to_cpu(node->totlen), buf_len, 810 ofs); 811 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 812 if (err) 813 return err; 814 buf_ofs = ofs; 815 node = (void *)buf; 816 } 817 err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s); 818 if (err) return err; 819 ofs += PAD(je32_to_cpu(node->totlen)); 820 break; 821 822 #ifdef CONFIG_JFFS2_FS_XATTR 823 case JFFS2_NODETYPE_XATTR: 824 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 825 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 826 jffs2_dbg(1, "Fewer than %d bytes (xattr node) left to end of buf. Reading 0x%x at 0x%08x\n", 827 je32_to_cpu(node->totlen), buf_len, 828 ofs); 829 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 830 if (err) 831 return err; 832 buf_ofs = ofs; 833 node = (void *)buf; 834 } 835 err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s); 836 if (err) 837 return err; 838 ofs += PAD(je32_to_cpu(node->totlen)); 839 break; 840 case JFFS2_NODETYPE_XREF: 841 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 842 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 843 jffs2_dbg(1, "Fewer than %d bytes (xref node) left to end of buf. Reading 0x%x at 0x%08x\n", 844 je32_to_cpu(node->totlen), buf_len, 845 ofs); 846 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 847 if (err) 848 return err; 849 buf_ofs = ofs; 850 node = (void *)buf; 851 } 852 err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s); 853 if (err) 854 return err; 855 ofs += PAD(je32_to_cpu(node->totlen)); 856 break; 857 #endif /* CONFIG_JFFS2_FS_XATTR */ 858 859 case JFFS2_NODETYPE_CLEANMARKER: 860 jffs2_dbg(1, "CLEANMARKER node found at 0x%08x\n", ofs); 861 if (je32_to_cpu(node->totlen) != c->cleanmarker_size) { 862 pr_notice("CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n", 863 ofs, je32_to_cpu(node->totlen), 864 c->cleanmarker_size); 865 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node))))) 866 return err; 867 ofs += PAD(sizeof(struct jffs2_unknown_node)); 868 } else if (jeb->first_node) { 869 pr_notice("CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", 870 ofs, jeb->offset); 871 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node))))) 872 return err; 873 ofs += PAD(sizeof(struct jffs2_unknown_node)); 874 } else { 875 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL); 876 877 ofs += PAD(c->cleanmarker_size); 878 } 879 break; 880 881 case JFFS2_NODETYPE_PADDING: 882 if (jffs2_sum_active()) 883 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen)); 884 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 885 return err; 886 ofs += PAD(je32_to_cpu(node->totlen)); 887 break; 888 889 default: 890 switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) { 891 case JFFS2_FEATURE_ROCOMPAT: 892 pr_notice("Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", 893 je16_to_cpu(node->nodetype), ofs); 894 c->flags |= JFFS2_SB_FLAG_RO; 895 if (!(jffs2_is_readonly(c))) 896 return -EROFS; 897 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 898 return err; 899 ofs += PAD(je32_to_cpu(node->totlen)); 900 break; 901 902 case JFFS2_FEATURE_INCOMPAT: 903 pr_notice("Incompatible feature node (0x%04x) found at offset 0x%08x\n", 904 je16_to_cpu(node->nodetype), ofs); 905 return -EINVAL; 906 907 case JFFS2_FEATURE_RWCOMPAT_DELETE: 908 jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", 909 je16_to_cpu(node->nodetype), ofs); 910 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 911 return err; 912 ofs += PAD(je32_to_cpu(node->totlen)); 913 break; 914 915 case JFFS2_FEATURE_RWCOMPAT_COPY: { 916 jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", 917 je16_to_cpu(node->nodetype), ofs); 918 919 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL); 920 921 /* We can't summarise nodes we don't grok */ 922 jffs2_sum_disable_collecting(s); 923 ofs += PAD(je32_to_cpu(node->totlen)); 924 break; 925 } 926 } 927 } 928 } 929 930 if (jffs2_sum_active()) { 931 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) { 932 dbg_summary("There is not enough space for " 933 "summary information, disabling for this jeb!\n"); 934 jffs2_sum_disable_collecting(s); 935 } 936 } 937 938 jffs2_dbg(1, "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n", 939 jeb->offset, jeb->free_size, jeb->dirty_size, 940 jeb->unchecked_size, jeb->used_size, jeb->wasted_size); 941 942 /* mark_node_obsolete can add to wasted !! */ 943 if (jeb->wasted_size) { 944 jeb->dirty_size += jeb->wasted_size; 945 c->dirty_size += jeb->wasted_size; 946 c->wasted_size -= jeb->wasted_size; 947 jeb->wasted_size = 0; 948 } 949 950 return jffs2_scan_classify_jeb(c, jeb); 951 } 952 953 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino) 954 { 955 struct jffs2_inode_cache *ic; 956 957 ic = jffs2_get_ino_cache(c, ino); 958 if (ic) 959 return ic; 960 961 if (ino > c->highest_ino) 962 c->highest_ino = ino; 963 964 ic = jffs2_alloc_inode_cache(); 965 if (!ic) { 966 pr_notice("%s(): allocation of inode cache failed\n", __func__); 967 return NULL; 968 } 969 memset(ic, 0, sizeof(*ic)); 970 971 ic->ino = ino; 972 ic->nodes = (void *)ic; 973 jffs2_add_ino_cache(c, ic); 974 if (ino == 1) 975 ic->pino_nlink = 1; 976 return ic; 977 } 978 979 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 980 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s) 981 { 982 struct jffs2_inode_cache *ic; 983 uint32_t crc, ino = je32_to_cpu(ri->ino); 984 985 jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs); 986 987 /* We do very little here now. Just check the ino# to which we should attribute 988 this node; we can do all the CRC checking etc. later. There's a tradeoff here -- 989 we used to scan the flash once only, reading everything we want from it into 990 memory, then building all our in-core data structures and freeing the extra 991 information. Now we allow the first part of the mount to complete a lot quicker, 992 but we have to go _back_ to the flash in order to finish the CRC checking, etc. 993 Which means that the _full_ amount of time to get to proper write mode with GC 994 operational may actually be _longer_ than before. Sucks to be me. */ 995 996 /* Check the node CRC in any case. */ 997 crc = crc32(0, ri, sizeof(*ri)-8); 998 if (crc != je32_to_cpu(ri->node_crc)) { 999 pr_notice("%s(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1000 __func__, ofs, je32_to_cpu(ri->node_crc), crc); 1001 /* 1002 * We believe totlen because the CRC on the node 1003 * _header_ was OK, just the node itself failed. 1004 */ 1005 return jffs2_scan_dirty_space(c, jeb, 1006 PAD(je32_to_cpu(ri->totlen))); 1007 } 1008 1009 ic = jffs2_get_ino_cache(c, ino); 1010 if (!ic) { 1011 ic = jffs2_scan_make_ino_cache(c, ino); 1012 if (!ic) 1013 return -ENOMEM; 1014 } 1015 1016 /* Wheee. It worked */ 1017 jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic); 1018 1019 jffs2_dbg(1, "Node is ino #%u, version %d. Range 0x%x-0x%x\n", 1020 je32_to_cpu(ri->ino), je32_to_cpu(ri->version), 1021 je32_to_cpu(ri->offset), 1022 je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)); 1023 1024 pseudo_random += je32_to_cpu(ri->version); 1025 1026 if (jffs2_sum_active()) { 1027 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset); 1028 } 1029 1030 return 0; 1031 } 1032 1033 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 1034 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s) 1035 { 1036 struct jffs2_full_dirent *fd; 1037 struct jffs2_inode_cache *ic; 1038 uint32_t checkedlen; 1039 uint32_t crc; 1040 int err; 1041 1042 jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs); 1043 1044 /* We don't get here unless the node is still valid, so we don't have to 1045 mask in the ACCURATE bit any more. */ 1046 crc = crc32(0, rd, sizeof(*rd)-8); 1047 1048 if (crc != je32_to_cpu(rd->node_crc)) { 1049 pr_notice("%s(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1050 __func__, ofs, je32_to_cpu(rd->node_crc), crc); 1051 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */ 1052 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen))))) 1053 return err; 1054 return 0; 1055 } 1056 1057 pseudo_random += je32_to_cpu(rd->version); 1058 1059 /* Should never happen. Did. (OLPC trac #4184)*/ 1060 checkedlen = strnlen(rd->name, rd->nsize); 1061 if (checkedlen < rd->nsize) { 1062 pr_err("Dirent at %08x has zeroes in name. Truncating to %d chars\n", 1063 ofs, checkedlen); 1064 } 1065 fd = jffs2_alloc_full_dirent(checkedlen+1); 1066 if (!fd) { 1067 return -ENOMEM; 1068 } 1069 memcpy(&fd->name, rd->name, checkedlen); 1070 fd->name[checkedlen] = 0; 1071 1072 crc = crc32(0, fd->name, rd->nsize); 1073 if (crc != je32_to_cpu(rd->name_crc)) { 1074 pr_notice("%s(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1075 __func__, ofs, je32_to_cpu(rd->name_crc), crc); 1076 jffs2_dbg(1, "Name for which CRC failed is (now) '%s', ino #%d\n", 1077 fd->name, je32_to_cpu(rd->ino)); 1078 jffs2_free_full_dirent(fd); 1079 /* FIXME: Why do we believe totlen? */ 1080 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */ 1081 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen))))) 1082 return err; 1083 return 0; 1084 } 1085 ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino)); 1086 if (!ic) { 1087 jffs2_free_full_dirent(fd); 1088 return -ENOMEM; 1089 } 1090 1091 fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd), 1092 PAD(je32_to_cpu(rd->totlen)), ic); 1093 1094 fd->next = NULL; 1095 fd->version = je32_to_cpu(rd->version); 1096 fd->ino = je32_to_cpu(rd->ino); 1097 fd->nhash = full_name_hash(fd->name, checkedlen); 1098 fd->type = rd->type; 1099 jffs2_add_fd_to_list(c, fd, &ic->scan_dents); 1100 1101 if (jffs2_sum_active()) { 1102 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset); 1103 } 1104 1105 return 0; 1106 } 1107 1108 static int count_list(struct list_head *l) 1109 { 1110 uint32_t count = 0; 1111 struct list_head *tmp; 1112 1113 list_for_each(tmp, l) { 1114 count++; 1115 } 1116 return count; 1117 } 1118 1119 /* Note: This breaks if list_empty(head). I don't care. You 1120 might, if you copy this code and use it elsewhere :) */ 1121 static void rotate_list(struct list_head *head, uint32_t count) 1122 { 1123 struct list_head *n = head->next; 1124 1125 list_del(head); 1126 while(count--) { 1127 n = n->next; 1128 } 1129 list_add(head, n); 1130 } 1131 1132 void jffs2_rotate_lists(struct jffs2_sb_info *c) 1133 { 1134 uint32_t x; 1135 uint32_t rotateby; 1136 1137 x = count_list(&c->clean_list); 1138 if (x) { 1139 rotateby = pseudo_random % x; 1140 rotate_list((&c->clean_list), rotateby); 1141 } 1142 1143 x = count_list(&c->very_dirty_list); 1144 if (x) { 1145 rotateby = pseudo_random % x; 1146 rotate_list((&c->very_dirty_list), rotateby); 1147 } 1148 1149 x = count_list(&c->dirty_list); 1150 if (x) { 1151 rotateby = pseudo_random % x; 1152 rotate_list((&c->dirty_list), rotateby); 1153 } 1154 1155 x = count_list(&c->erasable_list); 1156 if (x) { 1157 rotateby = pseudo_random % x; 1158 rotate_list((&c->erasable_list), rotateby); 1159 } 1160 1161 if (c->nr_erasing_blocks) { 1162 rotateby = pseudo_random % c->nr_erasing_blocks; 1163 rotate_list((&c->erase_pending_list), rotateby); 1164 } 1165 1166 if (c->nr_free_blocks) { 1167 rotateby = pseudo_random % c->nr_free_blocks; 1168 rotate_list((&c->free_list), rotateby); 1169 } 1170 } 1171