1 /* 2 * JFFS2 -- Journalling Flash File System, Version 2. 3 * 4 * Copyright (C) 2001-2003 Red Hat, Inc. 5 * 6 * Created by David Woodhouse <dwmw2@infradead.org> 7 * 8 * For licensing information, see the file 'LICENCE' in this directory. 9 * 10 * $Id: scan.c,v 1.125 2005/09/30 13:59:13 dedekind Exp $ 11 * 12 */ 13 #include <linux/kernel.h> 14 #include <linux/sched.h> 15 #include <linux/slab.h> 16 #include <linux/mtd/mtd.h> 17 #include <linux/pagemap.h> 18 #include <linux/crc32.h> 19 #include <linux/compiler.h> 20 #include "nodelist.h" 21 #include "summary.h" 22 #include "debug.h" 23 24 #define DEFAULT_EMPTY_SCAN_SIZE 1024 25 26 #define noisy_printk(noise, args...) do { \ 27 if (*(noise)) { \ 28 printk(KERN_NOTICE args); \ 29 (*(noise))--; \ 30 if (!(*(noise))) { \ 31 printk(KERN_NOTICE "Further such events for this erase block will not be printed\n"); \ 32 } \ 33 } \ 34 } while(0) 35 36 static uint32_t pseudo_random; 37 38 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 39 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s); 40 41 /* These helper functions _must_ increase ofs and also do the dirty/used space accounting. 42 * Returning an error will abort the mount - bad checksums etc. should just mark the space 43 * as dirty. 44 */ 45 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 46 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s); 47 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 48 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s); 49 50 static inline int min_free(struct jffs2_sb_info *c) 51 { 52 uint32_t min = 2 * sizeof(struct jffs2_raw_inode); 53 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 54 if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize) 55 return c->wbuf_pagesize; 56 #endif 57 return min; 58 59 } 60 61 static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) { 62 if (sector_size < DEFAULT_EMPTY_SCAN_SIZE) 63 return sector_size; 64 else 65 return DEFAULT_EMPTY_SCAN_SIZE; 66 } 67 68 static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb) 69 { 70 int ret; 71 72 if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1))) 73 return ret; 74 if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size))) 75 return ret; 76 /* Turned wasted size into dirty, since we apparently 77 think it's recoverable now. */ 78 jeb->dirty_size += jeb->wasted_size; 79 c->dirty_size += jeb->wasted_size; 80 c->wasted_size -= jeb->wasted_size; 81 jeb->wasted_size = 0; 82 if (VERYDIRTY(c, jeb->dirty_size)) { 83 list_add(&jeb->list, &c->very_dirty_list); 84 } else { 85 list_add(&jeb->list, &c->dirty_list); 86 } 87 return 0; 88 } 89 90 int jffs2_scan_medium(struct jffs2_sb_info *c) 91 { 92 int i, ret; 93 uint32_t empty_blocks = 0, bad_blocks = 0; 94 unsigned char *flashbuf = NULL; 95 uint32_t buf_size = 0; 96 struct jffs2_summary *s = NULL; /* summary info collected by the scan process */ 97 #ifndef __ECOS 98 size_t pointlen; 99 100 if (c->mtd->point) { 101 ret = c->mtd->point (c->mtd, 0, c->mtd->size, &pointlen, &flashbuf); 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, flashbuf, 0, c->mtd->size); 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 = kmalloc(sizeof(struct jffs2_summary), GFP_KERNEL); 132 if (!s) { 133 JFFS2_WARNING("Can't allocate memory for summary\n"); 134 return -ENOMEM; 135 } 136 memset(s, 0, sizeof(struct jffs2_summary)); 137 } 138 139 for (i=0; i<c->nr_blocks; i++) { 140 struct jffs2_eraseblock *jeb = &c->blocks[i]; 141 142 /* reset summary info for next eraseblock scan */ 143 jffs2_sum_reset_collected(s); 144 145 ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset), 146 buf_size, s); 147 148 if (ret < 0) 149 goto out; 150 151 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 152 153 /* Now decide which list to put it on */ 154 switch(ret) { 155 case BLK_STATE_ALLFF: 156 /* 157 * Empty block. Since we can't be sure it 158 * was entirely erased, we just queue it for erase 159 * again. It will be marked as such when the erase 160 * is complete. Meanwhile we still count it as empty 161 * for later checks. 162 */ 163 empty_blocks++; 164 list_add(&jeb->list, &c->erase_pending_list); 165 c->nr_erasing_blocks++; 166 break; 167 168 case BLK_STATE_CLEANMARKER: 169 /* Only a CLEANMARKER node is valid */ 170 if (!jeb->dirty_size) { 171 /* It's actually free */ 172 list_add(&jeb->list, &c->free_list); 173 c->nr_free_blocks++; 174 } else { 175 /* Dirt */ 176 D1(printk(KERN_DEBUG "Adding all-dirty block at 0x%08x to erase_pending_list\n", jeb->offset)); 177 list_add(&jeb->list, &c->erase_pending_list); 178 c->nr_erasing_blocks++; 179 } 180 break; 181 182 case BLK_STATE_CLEAN: 183 /* Full (or almost full) of clean data. Clean list */ 184 list_add(&jeb->list, &c->clean_list); 185 break; 186 187 case BLK_STATE_PARTDIRTY: 188 /* Some data, but not full. Dirty list. */ 189 /* We want to remember the block with most free space 190 and stick it in the 'nextblock' position to start writing to it. */ 191 if (jeb->free_size > min_free(c) && 192 (!c->nextblock || c->nextblock->free_size < jeb->free_size)) { 193 /* Better candidate for the next writes to go to */ 194 if (c->nextblock) { 195 ret = file_dirty(c, c->nextblock); 196 if (ret) 197 return ret; 198 /* deleting summary information of the old nextblock */ 199 jffs2_sum_reset_collected(c->summary); 200 } 201 /* update collected summary information for the current nextblock */ 202 jffs2_sum_move_collected(c, s); 203 D1(printk(KERN_DEBUG "jffs2_scan_medium(): new nextblock = 0x%08x\n", jeb->offset)); 204 c->nextblock = jeb; 205 } else { 206 ret = file_dirty(c, jeb); 207 if (ret) 208 return ret; 209 } 210 break; 211 212 case BLK_STATE_ALLDIRTY: 213 /* Nothing valid - not even a clean marker. Needs erasing. */ 214 /* For now we just put it on the erasing list. We'll start the erases later */ 215 D1(printk(KERN_NOTICE "JFFS2: Erase block at 0x%08x is not formatted. It will be erased\n", jeb->offset)); 216 list_add(&jeb->list, &c->erase_pending_list); 217 c->nr_erasing_blocks++; 218 break; 219 220 case BLK_STATE_BADBLOCK: 221 D1(printk(KERN_NOTICE "JFFS2: Block at 0x%08x is bad\n", jeb->offset)); 222 list_add(&jeb->list, &c->bad_list); 223 c->bad_size += c->sector_size; 224 c->free_size -= c->sector_size; 225 bad_blocks++; 226 break; 227 default: 228 printk(KERN_WARNING "jffs2_scan_medium(): unknown block state\n"); 229 BUG(); 230 } 231 } 232 233 /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */ 234 if (c->nextblock && (c->nextblock->dirty_size)) { 235 c->nextblock->wasted_size += c->nextblock->dirty_size; 236 c->wasted_size += c->nextblock->dirty_size; 237 c->dirty_size -= c->nextblock->dirty_size; 238 c->nextblock->dirty_size = 0; 239 } 240 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 241 if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) { 242 /* If we're going to start writing into a block which already 243 contains data, and the end of the data isn't page-aligned, 244 skip a little and align it. */ 245 246 uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize; 247 248 D1(printk(KERN_DEBUG "jffs2_scan_medium(): Skipping %d bytes in nextblock to ensure page alignment\n", 249 skip)); 250 jffs2_prealloc_raw_node_refs(c, c->nextblock, 1); 251 jffs2_scan_dirty_space(c, c->nextblock, skip); 252 } 253 #endif 254 if (c->nr_erasing_blocks) { 255 if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) { 256 printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n"); 257 printk(KERN_NOTICE "empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",empty_blocks,bad_blocks,c->nr_blocks); 258 ret = -EIO; 259 goto out; 260 } 261 jffs2_erase_pending_trigger(c); 262 } 263 ret = 0; 264 out: 265 if (buf_size) 266 kfree(flashbuf); 267 #ifndef __ECOS 268 else 269 c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size); 270 #endif 271 if (s) 272 kfree(s); 273 274 return ret; 275 } 276 277 int jffs2_fill_scan_buf (struct jffs2_sb_info *c, void *buf, 278 uint32_t ofs, uint32_t len) 279 { 280 int ret; 281 size_t retlen; 282 283 ret = jffs2_flash_read(c, ofs, len, &retlen, buf); 284 if (ret) { 285 D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", len, ofs, ret)); 286 return ret; 287 } 288 if (retlen < len) { 289 D1(printk(KERN_WARNING "Read at 0x%x gave only 0x%zx bytes\n", ofs, retlen)); 290 return -EIO; 291 } 292 return 0; 293 } 294 295 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb) 296 { 297 if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size 298 && (!jeb->first_node || !ref_next(jeb->first_node)) ) 299 return BLK_STATE_CLEANMARKER; 300 301 /* move blocks with max 4 byte dirty space to cleanlist */ 302 else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) { 303 c->dirty_size -= jeb->dirty_size; 304 c->wasted_size += jeb->dirty_size; 305 jeb->wasted_size += jeb->dirty_size; 306 jeb->dirty_size = 0; 307 return BLK_STATE_CLEAN; 308 } else if (jeb->used_size || jeb->unchecked_size) 309 return BLK_STATE_PARTDIRTY; 310 else 311 return BLK_STATE_ALLDIRTY; 312 } 313 314 #ifdef CONFIG_JFFS2_FS_XATTR 315 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 316 struct jffs2_raw_xattr *rx, uint32_t ofs, 317 struct jffs2_summary *s) 318 { 319 struct jffs2_xattr_datum *xd; 320 uint32_t totlen, crc; 321 int err; 322 323 crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4); 324 if (crc != je32_to_cpu(rx->node_crc)) { 325 if (je32_to_cpu(rx->node_crc) != 0xffffffff) 326 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n", 327 ofs, je32_to_cpu(rx->node_crc), crc); 328 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen)))) 329 return err; 330 return 0; 331 } 332 333 totlen = PAD(sizeof(*rx) + rx->name_len + 1 + je16_to_cpu(rx->value_len)); 334 if (totlen != je32_to_cpu(rx->totlen)) { 335 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n", 336 ofs, je32_to_cpu(rx->totlen), totlen); 337 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen)))) 338 return err; 339 return 0; 340 } 341 342 xd = jffs2_setup_xattr_datum(c, je32_to_cpu(rx->xid), je32_to_cpu(rx->version)); 343 if (IS_ERR(xd)) { 344 if (PTR_ERR(xd) == -EEXIST) { 345 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rx->totlen))))) 346 return err; 347 return 0; 348 } 349 return PTR_ERR(xd); 350 } 351 xd->xprefix = rx->xprefix; 352 xd->name_len = rx->name_len; 353 xd->value_len = je16_to_cpu(rx->value_len); 354 xd->data_crc = je32_to_cpu(rx->data_crc); 355 356 xd->node = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL); 357 /* FIXME */ xd->node->next_in_ino = (void *)xd; 358 359 if (jffs2_sum_active()) 360 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset); 361 dbg_xattr("scaning xdatum at %#08x (xid=%u, version=%u)\n", 362 ofs, xd->xid, xd->version); 363 return 0; 364 } 365 366 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 367 struct jffs2_raw_xref *rr, uint32_t ofs, 368 struct jffs2_summary *s) 369 { 370 struct jffs2_xattr_ref *ref; 371 uint32_t crc; 372 int err; 373 374 crc = crc32(0, rr, sizeof(*rr) - 4); 375 if (crc != je32_to_cpu(rr->node_crc)) { 376 if (je32_to_cpu(rr->node_crc) != 0xffffffff) 377 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n", 378 ofs, je32_to_cpu(rr->node_crc), crc); 379 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen))))) 380 return err; 381 return 0; 382 } 383 384 if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) { 385 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n", 386 ofs, je32_to_cpu(rr->totlen), 387 PAD(sizeof(struct jffs2_raw_xref))); 388 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen)))) 389 return err; 390 return 0; 391 } 392 393 ref = jffs2_alloc_xattr_ref(); 394 if (!ref) 395 return -ENOMEM; 396 397 /* BEFORE jffs2_build_xattr_subsystem() called, 398 * ref->xid is used to store 32bit xid, xd is not used 399 * ref->ino is used to store 32bit inode-number, ic is not used 400 * Thoes variables are declared as union, thus using those 401 * are exclusive. In a similar way, ref->next is temporarily 402 * used to chain all xattr_ref object. It's re-chained to 403 * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly. 404 */ 405 ref->ino = je32_to_cpu(rr->ino); 406 ref->xid = je32_to_cpu(rr->xid); 407 ref->next = c->xref_temp; 408 c->xref_temp = ref; 409 410 ref->node = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), NULL); 411 /* FIXME */ ref->node->next_in_ino = (void *)ref; 412 413 if (jffs2_sum_active()) 414 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset); 415 dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n", 416 ofs, ref->xid, ref->ino); 417 return 0; 418 } 419 #endif 420 421 /* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into 422 the flash, XIP-style */ 423 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 424 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) { 425 struct jffs2_unknown_node *node; 426 struct jffs2_unknown_node crcnode; 427 uint32_t ofs, prevofs; 428 uint32_t hdr_crc, buf_ofs, buf_len; 429 int err; 430 int noise = 0; 431 432 433 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 434 int cleanmarkerfound = 0; 435 #endif 436 437 ofs = jeb->offset; 438 prevofs = jeb->offset - 1; 439 440 D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs)); 441 442 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 443 if (jffs2_cleanmarker_oob(c)) { 444 int ret = jffs2_check_nand_cleanmarker(c, jeb); 445 D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret)); 446 /* Even if it's not found, we still scan to see 447 if the block is empty. We use this information 448 to decide whether to erase it or not. */ 449 switch (ret) { 450 case 0: cleanmarkerfound = 1; break; 451 case 1: break; 452 case 2: return BLK_STATE_BADBLOCK; 453 case 3: return BLK_STATE_ALLDIRTY; /* Block has failed to erase min. once */ 454 default: return ret; 455 } 456 } 457 #endif 458 459 if (jffs2_sum_active()) { 460 struct jffs2_sum_marker *sm; 461 void *sumptr = NULL; 462 uint32_t sumlen; 463 464 if (!buf_size) { 465 /* XIP case. Just look, point at the summary if it's there */ 466 sm = (void *)buf + c->sector_size - sizeof(*sm); 467 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) { 468 sumptr = buf + je32_to_cpu(sm->offset); 469 sumlen = c->sector_size - je32_to_cpu(sm->offset); 470 } 471 } else { 472 /* If NAND flash, read a whole page of it. Else just the end */ 473 if (c->wbuf_pagesize) 474 buf_len = c->wbuf_pagesize; 475 else 476 buf_len = sizeof(*sm); 477 478 /* Read as much as we want into the _end_ of the preallocated buffer */ 479 err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, 480 jeb->offset + c->sector_size - buf_len, 481 buf_len); 482 if (err) 483 return err; 484 485 sm = (void *)buf + buf_size - sizeof(*sm); 486 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) { 487 sumlen = c->sector_size - je32_to_cpu(sm->offset); 488 sumptr = buf + buf_size - sumlen; 489 490 /* Now, make sure the summary itself is available */ 491 if (sumlen > buf_size) { 492 /* Need to kmalloc for this. */ 493 sumptr = kmalloc(sumlen, GFP_KERNEL); 494 if (!sumptr) 495 return -ENOMEM; 496 memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len); 497 } 498 if (buf_len < sumlen) { 499 /* Need to read more so that the entire summary node is present */ 500 err = jffs2_fill_scan_buf(c, sumptr, 501 jeb->offset + c->sector_size - sumlen, 502 sumlen - buf_len); 503 if (err) 504 return err; 505 } 506 } 507 508 } 509 510 if (sumptr) { 511 err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random); 512 513 if (buf_size && sumlen > buf_size) 514 kfree(sumptr); 515 /* If it returns with a real error, bail. 516 If it returns positive, that's a block classification 517 (i.e. BLK_STATE_xxx) so return that too. 518 If it returns zero, fall through to full scan. */ 519 if (err) 520 return err; 521 } 522 } 523 524 buf_ofs = jeb->offset; 525 526 if (!buf_size) { 527 /* This is the XIP case -- we're reading _directly_ from the flash chip */ 528 buf_len = c->sector_size; 529 } else { 530 buf_len = EMPTY_SCAN_SIZE(c->sector_size); 531 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len); 532 if (err) 533 return err; 534 } 535 536 /* We temporarily use 'ofs' as a pointer into the buffer/jeb */ 537 ofs = 0; 538 539 /* Scan only 4KiB of 0xFF before declaring it's empty */ 540 while(ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF) 541 ofs += 4; 542 543 if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) { 544 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 545 if (jffs2_cleanmarker_oob(c)) { 546 /* scan oob, take care of cleanmarker */ 547 int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound); 548 D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret)); 549 switch (ret) { 550 case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF; 551 case 1: return BLK_STATE_ALLDIRTY; 552 default: return ret; 553 } 554 } 555 #endif 556 D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset)); 557 if (c->cleanmarker_size == 0) 558 return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */ 559 else 560 return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */ 561 } 562 if (ofs) { 563 D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset, 564 jeb->offset + ofs)); 565 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1))) 566 return err; 567 if ((err = jffs2_scan_dirty_space(c, jeb, ofs))) 568 return err; 569 } 570 571 /* Now ofs is a complete physical flash offset as it always was... */ 572 ofs += jeb->offset; 573 574 noise = 10; 575 576 dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset); 577 578 scan_more: 579 while(ofs < jeb->offset + c->sector_size) { 580 581 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 582 583 /* Make sure there are node refs available for use */ 584 err = jffs2_prealloc_raw_node_refs(c, jeb, 2); 585 if (err) 586 return err; 587 588 cond_resched(); 589 590 if (ofs & 3) { 591 printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs); 592 ofs = PAD(ofs); 593 continue; 594 } 595 if (ofs == prevofs) { 596 printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs); 597 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 598 return err; 599 ofs += 4; 600 continue; 601 } 602 prevofs = ofs; 603 604 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) { 605 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), 606 jeb->offset, c->sector_size, ofs, sizeof(*node))); 607 if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs))) 608 return err; 609 break; 610 } 611 612 if (buf_ofs + buf_len < ofs + sizeof(*node)) { 613 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 614 D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n", 615 sizeof(struct jffs2_unknown_node), buf_len, ofs)); 616 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 617 if (err) 618 return err; 619 buf_ofs = ofs; 620 } 621 622 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs]; 623 624 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) { 625 uint32_t inbuf_ofs; 626 uint32_t empty_start; 627 628 empty_start = ofs; 629 ofs += 4; 630 631 D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs)); 632 more_empty: 633 inbuf_ofs = ofs - buf_ofs; 634 while (inbuf_ofs < buf_len) { 635 if (*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff) { 636 printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n", 637 empty_start, ofs); 638 if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start))) 639 return err; 640 goto scan_more; 641 } 642 643 inbuf_ofs+=4; 644 ofs += 4; 645 } 646 /* Ran off end. */ 647 D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs)); 648 649 /* If we're only checking the beginning of a block with a cleanmarker, 650 bail now */ 651 if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) && 652 c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) { 653 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size))); 654 return BLK_STATE_CLEANMARKER; 655 } 656 657 /* See how much more there is to read in this eraseblock... */ 658 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 659 if (!buf_len) { 660 /* No more to read. Break out of main loop without marking 661 this range of empty space as dirty (because it's not) */ 662 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n", 663 empty_start)); 664 break; 665 } 666 D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs)); 667 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 668 if (err) 669 return err; 670 buf_ofs = ofs; 671 goto more_empty; 672 } 673 674 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) { 675 printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs); 676 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 677 return err; 678 ofs += 4; 679 continue; 680 } 681 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) { 682 D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs)); 683 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 684 return err; 685 ofs += 4; 686 continue; 687 } 688 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) { 689 printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs); 690 printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n"); 691 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 692 return err; 693 ofs += 4; 694 continue; 695 } 696 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) { 697 /* OK. We're out of possibilities. Whinge and move on */ 698 noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n", 699 JFFS2_MAGIC_BITMASK, ofs, 700 je16_to_cpu(node->magic)); 701 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 702 return err; 703 ofs += 4; 704 continue; 705 } 706 /* We seem to have a node of sorts. Check the CRC */ 707 crcnode.magic = node->magic; 708 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE); 709 crcnode.totlen = node->totlen; 710 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4); 711 712 if (hdr_crc != je32_to_cpu(node->hdr_crc)) { 713 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", 714 ofs, je16_to_cpu(node->magic), 715 je16_to_cpu(node->nodetype), 716 je32_to_cpu(node->totlen), 717 je32_to_cpu(node->hdr_crc), 718 hdr_crc); 719 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 720 return err; 721 ofs += 4; 722 continue; 723 } 724 725 if (ofs + je32_to_cpu(node->totlen) > 726 jeb->offset + c->sector_size) { 727 /* Eep. Node goes over the end of the erase block. */ 728 printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n", 729 ofs, je32_to_cpu(node->totlen)); 730 printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n"); 731 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 732 return err; 733 ofs += 4; 734 continue; 735 } 736 737 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) { 738 /* Wheee. This is an obsoleted node */ 739 D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs)); 740 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 741 return err; 742 ofs += PAD(je32_to_cpu(node->totlen)); 743 continue; 744 } 745 746 switch(je16_to_cpu(node->nodetype)) { 747 case JFFS2_NODETYPE_INODE: 748 if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) { 749 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 750 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n", 751 sizeof(struct jffs2_raw_inode), buf_len, ofs)); 752 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 753 if (err) 754 return err; 755 buf_ofs = ofs; 756 node = (void *)buf; 757 } 758 err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s); 759 if (err) return err; 760 ofs += PAD(je32_to_cpu(node->totlen)); 761 break; 762 763 case JFFS2_NODETYPE_DIRENT: 764 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 765 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 766 D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n", 767 je32_to_cpu(node->totlen), buf_len, ofs)); 768 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 769 if (err) 770 return err; 771 buf_ofs = ofs; 772 node = (void *)buf; 773 } 774 err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s); 775 if (err) return err; 776 ofs += PAD(je32_to_cpu(node->totlen)); 777 break; 778 779 #ifdef CONFIG_JFFS2_FS_XATTR 780 case JFFS2_NODETYPE_XATTR: 781 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 782 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 783 D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)" 784 " left to end of buf. Reading 0x%x at 0x%08x\n", 785 je32_to_cpu(node->totlen), buf_len, ofs)); 786 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 787 if (err) 788 return err; 789 buf_ofs = ofs; 790 node = (void *)buf; 791 } 792 err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s); 793 if (err) 794 return err; 795 ofs += PAD(je32_to_cpu(node->totlen)); 796 break; 797 case JFFS2_NODETYPE_XREF: 798 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 799 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 800 D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)" 801 " left to end of buf. Reading 0x%x at 0x%08x\n", 802 je32_to_cpu(node->totlen), buf_len, ofs)); 803 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 804 if (err) 805 return err; 806 buf_ofs = ofs; 807 node = (void *)buf; 808 } 809 err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s); 810 if (err) 811 return err; 812 ofs += PAD(je32_to_cpu(node->totlen)); 813 break; 814 #endif /* CONFIG_JFFS2_FS_XATTR */ 815 816 case JFFS2_NODETYPE_CLEANMARKER: 817 D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs)); 818 if (je32_to_cpu(node->totlen) != c->cleanmarker_size) { 819 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n", 820 ofs, je32_to_cpu(node->totlen), c->cleanmarker_size); 821 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node))))) 822 return err; 823 ofs += PAD(sizeof(struct jffs2_unknown_node)); 824 } else if (jeb->first_node) { 825 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset); 826 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node))))) 827 return err; 828 ofs += PAD(sizeof(struct jffs2_unknown_node)); 829 } else { 830 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL); 831 832 ofs += PAD(c->cleanmarker_size); 833 } 834 break; 835 836 case JFFS2_NODETYPE_PADDING: 837 if (jffs2_sum_active()) 838 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen)); 839 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 840 return err; 841 ofs += PAD(je32_to_cpu(node->totlen)); 842 break; 843 844 default: 845 switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) { 846 case JFFS2_FEATURE_ROCOMPAT: 847 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs); 848 c->flags |= JFFS2_SB_FLAG_RO; 849 if (!(jffs2_is_readonly(c))) 850 return -EROFS; 851 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 852 return err; 853 ofs += PAD(je32_to_cpu(node->totlen)); 854 break; 855 856 case JFFS2_FEATURE_INCOMPAT: 857 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs); 858 return -EINVAL; 859 860 case JFFS2_FEATURE_RWCOMPAT_DELETE: 861 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs)); 862 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 863 return err; 864 ofs += PAD(je32_to_cpu(node->totlen)); 865 break; 866 867 case JFFS2_FEATURE_RWCOMPAT_COPY: { 868 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs)); 869 870 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL); 871 872 /* We can't summarise nodes we don't grok */ 873 jffs2_sum_disable_collecting(s); 874 ofs += PAD(je32_to_cpu(node->totlen)); 875 break; 876 } 877 } 878 } 879 } 880 881 if (jffs2_sum_active()) { 882 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) { 883 dbg_summary("There is not enough space for " 884 "summary information, disabling for this jeb!\n"); 885 jffs2_sum_disable_collecting(s); 886 } 887 } 888 889 D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n", 890 jeb->offset,jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size, jeb->wasted_size)); 891 892 /* mark_node_obsolete can add to wasted !! */ 893 if (jeb->wasted_size) { 894 jeb->dirty_size += jeb->wasted_size; 895 c->dirty_size += jeb->wasted_size; 896 c->wasted_size -= jeb->wasted_size; 897 jeb->wasted_size = 0; 898 } 899 900 return jffs2_scan_classify_jeb(c, jeb); 901 } 902 903 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino) 904 { 905 struct jffs2_inode_cache *ic; 906 907 ic = jffs2_get_ino_cache(c, ino); 908 if (ic) 909 return ic; 910 911 if (ino > c->highest_ino) 912 c->highest_ino = ino; 913 914 ic = jffs2_alloc_inode_cache(); 915 if (!ic) { 916 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n"); 917 return NULL; 918 } 919 memset(ic, 0, sizeof(*ic)); 920 921 ic->ino = ino; 922 ic->nodes = (void *)ic; 923 jffs2_add_ino_cache(c, ic); 924 if (ino == 1) 925 ic->nlink = 1; 926 return ic; 927 } 928 929 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 930 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s) 931 { 932 struct jffs2_inode_cache *ic; 933 uint32_t ino = je32_to_cpu(ri->ino); 934 int err; 935 936 D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs)); 937 938 /* We do very little here now. Just check the ino# to which we should attribute 939 this node; we can do all the CRC checking etc. later. There's a tradeoff here -- 940 we used to scan the flash once only, reading everything we want from it into 941 memory, then building all our in-core data structures and freeing the extra 942 information. Now we allow the first part of the mount to complete a lot quicker, 943 but we have to go _back_ to the flash in order to finish the CRC checking, etc. 944 Which means that the _full_ amount of time to get to proper write mode with GC 945 operational may actually be _longer_ than before. Sucks to be me. */ 946 947 ic = jffs2_get_ino_cache(c, ino); 948 if (!ic) { 949 /* Inocache get failed. Either we read a bogus ino# or it's just genuinely the 950 first node we found for this inode. Do a CRC check to protect against the former 951 case */ 952 uint32_t crc = crc32(0, ri, sizeof(*ri)-8); 953 954 if (crc != je32_to_cpu(ri->node_crc)) { 955 printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 956 ofs, je32_to_cpu(ri->node_crc), crc); 957 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */ 958 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(ri->totlen))))) 959 return err; 960 return 0; 961 } 962 ic = jffs2_scan_make_ino_cache(c, ino); 963 if (!ic) 964 return -ENOMEM; 965 } 966 967 /* Wheee. It worked */ 968 jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic); 969 970 D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n", 971 je32_to_cpu(ri->ino), je32_to_cpu(ri->version), 972 je32_to_cpu(ri->offset), 973 je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize))); 974 975 pseudo_random += je32_to_cpu(ri->version); 976 977 if (jffs2_sum_active()) { 978 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset); 979 } 980 981 return 0; 982 } 983 984 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 985 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s) 986 { 987 struct jffs2_full_dirent *fd; 988 struct jffs2_inode_cache *ic; 989 uint32_t crc; 990 int err; 991 992 D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs)); 993 994 /* We don't get here unless the node is still valid, so we don't have to 995 mask in the ACCURATE bit any more. */ 996 crc = crc32(0, rd, sizeof(*rd)-8); 997 998 if (crc != je32_to_cpu(rd->node_crc)) { 999 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1000 ofs, je32_to_cpu(rd->node_crc), crc); 1001 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */ 1002 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen))))) 1003 return err; 1004 return 0; 1005 } 1006 1007 pseudo_random += je32_to_cpu(rd->version); 1008 1009 fd = jffs2_alloc_full_dirent(rd->nsize+1); 1010 if (!fd) { 1011 return -ENOMEM; 1012 } 1013 memcpy(&fd->name, rd->name, rd->nsize); 1014 fd->name[rd->nsize] = 0; 1015 1016 crc = crc32(0, fd->name, rd->nsize); 1017 if (crc != je32_to_cpu(rd->name_crc)) { 1018 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1019 ofs, je32_to_cpu(rd->name_crc), crc); 1020 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino))); 1021 jffs2_free_full_dirent(fd); 1022 /* FIXME: Why do we believe totlen? */ 1023 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */ 1024 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen))))) 1025 return err; 1026 return 0; 1027 } 1028 ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino)); 1029 if (!ic) { 1030 jffs2_free_full_dirent(fd); 1031 return -ENOMEM; 1032 } 1033 1034 fd->raw = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rd->totlen)), ic); 1035 1036 fd->next = NULL; 1037 fd->version = je32_to_cpu(rd->version); 1038 fd->ino = je32_to_cpu(rd->ino); 1039 fd->nhash = full_name_hash(fd->name, rd->nsize); 1040 fd->type = rd->type; 1041 jffs2_add_fd_to_list(c, fd, &ic->scan_dents); 1042 1043 if (jffs2_sum_active()) { 1044 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset); 1045 } 1046 1047 return 0; 1048 } 1049 1050 static int count_list(struct list_head *l) 1051 { 1052 uint32_t count = 0; 1053 struct list_head *tmp; 1054 1055 list_for_each(tmp, l) { 1056 count++; 1057 } 1058 return count; 1059 } 1060 1061 /* Note: This breaks if list_empty(head). I don't care. You 1062 might, if you copy this code and use it elsewhere :) */ 1063 static void rotate_list(struct list_head *head, uint32_t count) 1064 { 1065 struct list_head *n = head->next; 1066 1067 list_del(head); 1068 while(count--) { 1069 n = n->next; 1070 } 1071 list_add(head, n); 1072 } 1073 1074 void jffs2_rotate_lists(struct jffs2_sb_info *c) 1075 { 1076 uint32_t x; 1077 uint32_t rotateby; 1078 1079 x = count_list(&c->clean_list); 1080 if (x) { 1081 rotateby = pseudo_random % x; 1082 rotate_list((&c->clean_list), rotateby); 1083 } 1084 1085 x = count_list(&c->very_dirty_list); 1086 if (x) { 1087 rotateby = pseudo_random % x; 1088 rotate_list((&c->very_dirty_list), rotateby); 1089 } 1090 1091 x = count_list(&c->dirty_list); 1092 if (x) { 1093 rotateby = pseudo_random % x; 1094 rotate_list((&c->dirty_list), rotateby); 1095 } 1096 1097 x = count_list(&c->erasable_list); 1098 if (x) { 1099 rotateby = pseudo_random % x; 1100 rotate_list((&c->erasable_list), rotateby); 1101 } 1102 1103 if (c->nr_erasing_blocks) { 1104 rotateby = pseudo_random % c->nr_erasing_blocks; 1105 rotate_list((&c->erase_pending_list), rotateby); 1106 } 1107 1108 if (c->nr_free_blocks) { 1109 rotateby = pseudo_random % c->nr_free_blocks; 1110 rotate_list((&c->free_list), rotateby); 1111 } 1112 } 1113