1/* 2 * JFFS2 -- Journalling Flash File System, Version 2. 3 * 4 * Copyright �� 2001-2007 Red Hat, Inc. 5 * 6 * Created by David Woodhouse <dwmw2@infradead.org> 7 * 8 * For licensing information, see the file 'LICENCE' in this directory. 9 * 10 */ 11 12#include <linux/kernel.h> 13#include <linux/sched.h> 14#include <linux/slab.h> 15#include <linux/mtd/mtd.h> 16#include <linux/pagemap.h> 17#include <linux/crc32.h> 18#include <linux/compiler.h> 19#include "nodelist.h" 20#include "summary.h" 21#include "debug.h" 22 23#define DEFAULT_EMPTY_SCAN_SIZE 1024 24 25#define noisy_printk(noise, args...) do { \ 26 if (*(noise)) { \ 27 printk(KERN_NOTICE args); \ 28 (*(noise))--; \ 29 if (!(*(noise))) { \ 30 printk(KERN_NOTICE "Further such events for this erase block will not be printed\n"); \ 31 } \ 32 } \ 33} while(0) 34 35static uint32_t pseudo_random; 36 37static 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 */ 44static 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); 46static 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 49static 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 60static 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 67static 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 89int jffs2_scan_medium(struct jffs2_sb_info *c) 90{ 91 int i, ret; 92 uint32_t empty_blocks = 0, bad_blocks = 0; 93 unsigned char *flashbuf = NULL; 94 uint32_t buf_size = 0; 95 struct jffs2_summary *s = NULL; /* summary info collected by the scan process */ 96#ifndef __ECOS 97 size_t pointlen; 98 99 if (c->mtd->point) { 100 ret = c->mtd->point (c->mtd, 0, c->mtd->size, &pointlen, &flashbuf); 101 if (!ret && pointlen < c->mtd->size) { 102 /* Don't muck about if it won't let us point to the whole flash */ 103 D1(printk(KERN_DEBUG "MTD point returned len too short: 0x%zx\n", pointlen)); 104 c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size); 105 flashbuf = NULL; 106 } 107 if (ret) 108 D1(printk(KERN_DEBUG "MTD point failed %d\n", ret)); 109 } 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 buf_size = c->sector_size; 116 else 117 buf_size = PAGE_SIZE; 118 119 /* Respect kmalloc limitations */ 120 if (buf_size > 128*1024) 121 buf_size = 128*1024; 122 123 D1(printk(KERN_DEBUG "Allocating readbuf of %d bytes\n", buf_size)); 124 flashbuf = kmalloc(buf_size, GFP_KERNEL); 125 if (!flashbuf) 126 return -ENOMEM; 127 } 128 129 if (jffs2_sum_active()) { 130 s = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL); 131 if (!s) { 132 kfree(flashbuf); 133 JFFS2_WARNING("Can't allocate memory for summary\n"); 134 return -ENOMEM; 135 } 136 } 137 138 for (i=0; i<c->nr_blocks; i++) { 139 struct jffs2_eraseblock *jeb = &c->blocks[i]; 140 141 cond_resched(); 142 143 /* reset summary info for next eraseblock scan */ 144 jffs2_sum_reset_collected(s); 145 146 ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset), 147 buf_size, s); 148 149 if (ret < 0) 150 goto out; 151 152 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 153 154 /* Now decide which list to put it on */ 155 switch(ret) { 156 case BLK_STATE_ALLFF: 157 /* 158 * Empty block. Since we can't be sure it 159 * was entirely erased, we just queue it for erase 160 * again. It will be marked as such when the erase 161 * is complete. Meanwhile we still count it as empty 162 * for later checks. 163 */ 164 empty_blocks++; 165 list_add(&jeb->list, &c->erase_pending_list); 166 c->nr_erasing_blocks++; 167 break; 168 169 case BLK_STATE_CLEANMARKER: 170 /* Only a CLEANMARKER node is valid */ 171 if (!jeb->dirty_size) { 172 /* It's actually free */ 173 list_add(&jeb->list, &c->free_list); 174 c->nr_free_blocks++; 175 } else { 176 /* Dirt */ 177 D1(printk(KERN_DEBUG "Adding all-dirty block at 0x%08x to erase_pending_list\n", jeb->offset)); 178 list_add(&jeb->list, &c->erase_pending_list); 179 c->nr_erasing_blocks++; 180 } 181 break; 182 183 case BLK_STATE_CLEAN: 184 /* Full (or almost full) of clean data. Clean list */ 185 list_add(&jeb->list, &c->clean_list); 186 break; 187 188 case BLK_STATE_PARTDIRTY: 189 /* Some data, but not full. Dirty list. */ 190 /* We want to remember the block with most free space 191 and stick it in the 'nextblock' position to start writing to it. */ 192 if (jeb->free_size > min_free(c) && 193 (!c->nextblock || c->nextblock->free_size < jeb->free_size)) { 194 /* Better candidate for the next writes to go to */ 195 if (c->nextblock) { 196 ret = file_dirty(c, c->nextblock); 197 if (ret) 198 return ret; 199 /* deleting summary information of the old nextblock */ 200 jffs2_sum_reset_collected(c->summary); 201 } 202 /* update collected summary information for the current nextblock */ 203 jffs2_sum_move_collected(c, s); 204 D1(printk(KERN_DEBUG "jffs2_scan_medium(): new nextblock = 0x%08x\n", jeb->offset)); 205 c->nextblock = jeb; 206 } else { 207 ret = file_dirty(c, jeb); 208 if (ret) 209 return ret; 210 } 211 break; 212 213 case BLK_STATE_ALLDIRTY: 214 /* Nothing valid - not even a clean marker. Needs erasing. */ 215 /* For now we just put it on the erasing list. We'll start the erases later */ 216 D1(printk(KERN_NOTICE "JFFS2: Erase block at 0x%08x is not formatted. It will be erased\n", jeb->offset)); 217 list_add(&jeb->list, &c->erase_pending_list); 218 c->nr_erasing_blocks++; 219 break; 220 221 case BLK_STATE_BADBLOCK: 222 D1(printk(KERN_NOTICE "JFFS2: Block at 0x%08x is bad\n", jeb->offset)); 223 list_add(&jeb->list, &c->bad_list); 224 c->bad_size += c->sector_size; 225 c->free_size -= c->sector_size; 226 bad_blocks++; 227 break; 228 default: 229 printk(KERN_WARNING "jffs2_scan_medium(): unknown block state\n"); 230 BUG(); 231 } 232 } 233 234 /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */ 235 if (c->nextblock && (c->nextblock->dirty_size)) { 236 c->nextblock->wasted_size += c->nextblock->dirty_size; 237 c->wasted_size += c->nextblock->dirty_size; 238 c->dirty_size -= c->nextblock->dirty_size; 239 c->nextblock->dirty_size = 0; 240 } 241#ifdef CONFIG_JFFS2_FS_WRITEBUFFER 242 if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) { 243 /* If we're going to start writing into a block which already 244 contains data, and the end of the data isn't page-aligned, 245 skip a little and align it. */ 246 247 uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize; 248 249 D1(printk(KERN_DEBUG "jffs2_scan_medium(): Skipping %d bytes in nextblock to ensure page alignment\n", 250 skip)); 251 jffs2_prealloc_raw_node_refs(c, c->nextblock, 1); 252 jffs2_scan_dirty_space(c, c->nextblock, skip); 253 } 254#endif 255 if (c->nr_erasing_blocks) { 256 if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) { 257 printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n"); 258 printk(KERN_NOTICE "empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",empty_blocks,bad_blocks,c->nr_blocks); 259 ret = -EIO; 260 goto out; 261 } 262 jffs2_erase_pending_trigger(c); 263 } 264 ret = 0; 265 out: 266 if (buf_size) 267 kfree(flashbuf); 268#ifndef __ECOS 269 else 270 c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size); 271#endif 272 if (s) 273 kfree(s); 274 275 return ret; 276} 277 278static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf, 279 uint32_t ofs, uint32_t len) 280{ 281 int ret; 282 size_t retlen; 283 284 ret = jffs2_flash_read(c, ofs, len, &retlen, buf); 285 if (ret) { 286 D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", len, ofs, ret)); 287 return ret; 288 } 289 if (retlen < len) { 290 D1(printk(KERN_WARNING "Read at 0x%x gave only 0x%zx bytes\n", ofs, retlen)); 291 return -EIO; 292 } 293 return 0; 294} 295 296int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb) 297{ 298 if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size 299 && (!jeb->first_node || !ref_next(jeb->first_node)) ) 300 return BLK_STATE_CLEANMARKER; 301 302 /* move blocks with max 4 byte dirty space to cleanlist */ 303 else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) { 304 c->dirty_size -= jeb->dirty_size; 305 c->wasted_size += jeb->dirty_size; 306 jeb->wasted_size += jeb->dirty_size; 307 jeb->dirty_size = 0; 308 return BLK_STATE_CLEAN; 309 } else if (jeb->used_size || jeb->unchecked_size) 310 return BLK_STATE_PARTDIRTY; 311 else 312 return BLK_STATE_ALLDIRTY; 313} 314 315#ifdef CONFIG_JFFS2_FS_XATTR 316static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 317 struct jffs2_raw_xattr *rx, uint32_t ofs, 318 struct jffs2_summary *s) 319{ 320 struct jffs2_xattr_datum *xd; 321 uint32_t xid, version, totlen, crc; 322 int err; 323 324 crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4); 325 if (crc != je32_to_cpu(rx->node_crc)) { 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 xid = je32_to_cpu(rx->xid); 334 version = je32_to_cpu(rx->version); 335 336 totlen = PAD(sizeof(struct jffs2_raw_xattr) 337 + rx->name_len + 1 + je16_to_cpu(rx->value_len)); 338 if (totlen != je32_to_cpu(rx->totlen)) { 339 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n", 340 ofs, je32_to_cpu(rx->totlen), totlen); 341 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen)))) 342 return err; 343 return 0; 344 } 345 346 xd = jffs2_setup_xattr_datum(c, xid, version); 347 if (IS_ERR(xd)) 348 return PTR_ERR(xd); 349 350 if (xd->version > version) { 351 struct jffs2_raw_node_ref *raw 352 = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL); 353 raw->next_in_ino = xd->node->next_in_ino; 354 xd->node->next_in_ino = raw; 355 } else { 356 xd->version = version; 357 xd->xprefix = rx->xprefix; 358 xd->name_len = rx->name_len; 359 xd->value_len = je16_to_cpu(rx->value_len); 360 xd->data_crc = je32_to_cpu(rx->data_crc); 361 362 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd); 363 } 364 365 if (jffs2_sum_active()) 366 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset); 367 dbg_xattr("scaning xdatum at %#08x (xid=%u, version=%u)\n", 368 ofs, xd->xid, xd->version); 369 return 0; 370} 371 372static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 373 struct jffs2_raw_xref *rr, uint32_t ofs, 374 struct jffs2_summary *s) 375{ 376 struct jffs2_xattr_ref *ref; 377 uint32_t crc; 378 int err; 379 380 crc = crc32(0, rr, sizeof(*rr) - 4); 381 if (crc != je32_to_cpu(rr->node_crc)) { 382 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n", 383 ofs, je32_to_cpu(rr->node_crc), crc); 384 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen))))) 385 return err; 386 return 0; 387 } 388 389 if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) { 390 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n", 391 ofs, je32_to_cpu(rr->totlen), 392 PAD(sizeof(struct jffs2_raw_xref))); 393 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen)))) 394 return err; 395 return 0; 396 } 397 398 ref = jffs2_alloc_xattr_ref(); 399 if (!ref) 400 return -ENOMEM; 401 402 /* BEFORE jffs2_build_xattr_subsystem() called, 403 * and AFTER xattr_ref is marked as a dead xref, 404 * ref->xid is used to store 32bit xid, xd is not used 405 * ref->ino is used to store 32bit inode-number, ic is not used 406 * Thoes variables are declared as union, thus using those 407 * are exclusive. In a similar way, ref->next is temporarily 408 * used to chain all xattr_ref object. It's re-chained to 409 * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly. 410 */ 411 ref->ino = je32_to_cpu(rr->ino); 412 ref->xid = je32_to_cpu(rr->xid); 413 ref->xseqno = je32_to_cpu(rr->xseqno); 414 if (ref->xseqno > c->highest_xseqno) 415 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER); 416 ref->next = c->xref_temp; 417 c->xref_temp = ref; 418 419 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref); 420 421 if (jffs2_sum_active()) 422 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset); 423 dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n", 424 ofs, ref->xid, ref->ino); 425 return 0; 426} 427#endif 428 429/* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into 430 the flash, XIP-style */ 431static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 432 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) { 433 struct jffs2_unknown_node *node; 434 struct jffs2_unknown_node crcnode; 435 uint32_t ofs, prevofs; 436 uint32_t hdr_crc, buf_ofs, buf_len; 437 int err; 438 int noise = 0; 439 440 441#ifdef CONFIG_JFFS2_FS_WRITEBUFFER 442 int cleanmarkerfound = 0; 443#endif 444 445 ofs = jeb->offset; 446 prevofs = jeb->offset - 1; 447 448 D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs)); 449 450#ifdef CONFIG_JFFS2_FS_WRITEBUFFER 451 if (jffs2_cleanmarker_oob(c)) { 452 int ret; 453 454 if (c->mtd->block_isbad(c->mtd, jeb->offset)) 455 return BLK_STATE_BADBLOCK; 456 457 ret = jffs2_check_nand_cleanmarker(c, jeb); 458 D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret)); 459 460 /* Even if it's not found, we still scan to see 461 if the block is empty. We use this information 462 to decide whether to erase it or not. */ 463 switch (ret) { 464 case 0: cleanmarkerfound = 1; break; 465 case 1: break; 466 default: return ret; 467 } 468 } 469#endif 470 471 if (jffs2_sum_active()) { 472 struct jffs2_sum_marker *sm; 473 void *sumptr = NULL; 474 uint32_t sumlen; 475 476 if (!buf_size) { 477 /* XIP case. Just look, point at the summary if it's there */ 478 sm = (void *)buf + c->sector_size - sizeof(*sm); 479 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) { 480 sumptr = buf + je32_to_cpu(sm->offset); 481 sumlen = c->sector_size - je32_to_cpu(sm->offset); 482 } 483 } else { 484 /* If NAND flash, read a whole page of it. Else just the end */ 485 if (c->wbuf_pagesize) 486 buf_len = c->wbuf_pagesize; 487 else 488 buf_len = sizeof(*sm); 489 490 /* Read as much as we want into the _end_ of the preallocated buffer */ 491 err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, 492 jeb->offset + c->sector_size - buf_len, 493 buf_len); 494 if (err) 495 return err; 496 497 sm = (void *)buf + buf_size - sizeof(*sm); 498 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) { 499 sumlen = c->sector_size - je32_to_cpu(sm->offset); 500 sumptr = buf + buf_size - sumlen; 501 502 /* Now, make sure the summary itself is available */ 503 if (sumlen > buf_size) { 504 /* Need to kmalloc for this. */ 505 sumptr = kmalloc(sumlen, GFP_KERNEL); 506 if (!sumptr) 507 return -ENOMEM; 508 memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len); 509 } 510 if (buf_len < sumlen) { 511 /* Need to read more so that the entire summary node is present */ 512 err = jffs2_fill_scan_buf(c, sumptr, 513 jeb->offset + c->sector_size - sumlen, 514 sumlen - buf_len); 515 if (err) 516 return err; 517 } 518 } 519 520 } 521 522 if (sumptr) { 523 err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random); 524 525 if (buf_size && sumlen > buf_size) 526 kfree(sumptr); 527 /* If it returns with a real error, bail. 528 If it returns positive, that's a block classification 529 (i.e. BLK_STATE_xxx) so return that too. 530 If it returns zero, fall through to full scan. */ 531 if (err) 532 return err; 533 } 534 } 535 536 buf_ofs = jeb->offset; 537 538 if (!buf_size) { 539 /* This is the XIP case -- we're reading _directly_ from the flash chip */ 540 buf_len = c->sector_size; 541 } else { 542 buf_len = EMPTY_SCAN_SIZE(c->sector_size); 543 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len); 544 if (err) 545 return err; 546 } 547 548 /* We temporarily use 'ofs' as a pointer into the buffer/jeb */ 549 ofs = 0; 550 551 /* Scan only 4KiB of 0xFF before declaring it's empty */ 552 while(ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF) 553 ofs += 4; 554 555 if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) { 556#ifdef CONFIG_JFFS2_FS_WRITEBUFFER 557 if (jffs2_cleanmarker_oob(c)) { 558 /* scan oob, take care of cleanmarker */ 559 int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound); 560 D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret)); 561 switch (ret) { 562 case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF; 563 case 1: return BLK_STATE_ALLDIRTY; 564 default: return ret; 565 } 566 } 567#endif 568 D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset)); 569 if (c->cleanmarker_size == 0) 570 return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */ 571 else 572 return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */ 573 } 574 if (ofs) { 575 D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset, 576 jeb->offset + ofs)); 577 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1))) 578 return err; 579 if ((err = jffs2_scan_dirty_space(c, jeb, ofs))) 580 return err; 581 } 582 583 /* Now ofs is a complete physical flash offset as it always was... */ 584 ofs += jeb->offset; 585 586 noise = 10; 587 588 dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset); 589 590scan_more: 591 while(ofs < jeb->offset + c->sector_size) { 592 593 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 594 595 /* Make sure there are node refs available for use */ 596 err = jffs2_prealloc_raw_node_refs(c, jeb, 2); 597 if (err) 598 return err; 599 600 cond_resched(); 601 602 if (ofs & 3) { 603 printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs); 604 ofs = PAD(ofs); 605 continue; 606 } 607 if (ofs == prevofs) { 608 printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs); 609 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 610 return err; 611 ofs += 4; 612 continue; 613 } 614 prevofs = ofs; 615 616 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) { 617 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), 618 jeb->offset, c->sector_size, ofs, sizeof(*node))); 619 if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs))) 620 return err; 621 break; 622 } 623 624 if (buf_ofs + buf_len < ofs + sizeof(*node)) { 625 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 626 D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n", 627 sizeof(struct jffs2_unknown_node), buf_len, ofs)); 628 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 629 if (err) 630 return err; 631 buf_ofs = ofs; 632 } 633 634 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs]; 635 636 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) { 637 uint32_t inbuf_ofs; 638 uint32_t empty_start, scan_end; 639 640 empty_start = ofs; 641 ofs += 4; 642 scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len); 643 644 D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs)); 645 more_empty: 646 inbuf_ofs = ofs - buf_ofs; 647 while (inbuf_ofs < scan_end) { 648 if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) { 649 printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n", 650 empty_start, ofs); 651 if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start))) 652 return err; 653 goto scan_more; 654 } 655 656 inbuf_ofs+=4; 657 ofs += 4; 658 } 659 /* Ran off end. */ 660 D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs)); 661 662 /* If we're only checking the beginning of a block with a cleanmarker, 663 bail now */ 664 if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) && 665 c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) { 666 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size))); 667 return BLK_STATE_CLEANMARKER; 668 } 669 if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */ 670 scan_end = buf_len; 671 goto more_empty; 672 } 673 674 /* See how much more there is to read in this eraseblock... */ 675 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 676 if (!buf_len) { 677 /* No more to read. Break out of main loop without marking 678 this range of empty space as dirty (because it's not) */ 679 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n", 680 empty_start)); 681 break; 682 } 683 /* point never reaches here */ 684 scan_end = buf_len; 685 D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs)); 686 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 687 if (err) 688 return err; 689 buf_ofs = ofs; 690 goto more_empty; 691 } 692 693 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) { 694 printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs); 695 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 696 return err; 697 ofs += 4; 698 continue; 699 } 700 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) { 701 D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs)); 702 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 703 return err; 704 ofs += 4; 705 continue; 706 } 707 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) { 708 printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs); 709 printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n"); 710 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 711 return err; 712 ofs += 4; 713 continue; 714 } 715 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) { 716 /* OK. We're out of possibilities. Whinge and move on */ 717 noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n", 718 JFFS2_MAGIC_BITMASK, ofs, 719 je16_to_cpu(node->magic)); 720 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 721 return err; 722 ofs += 4; 723 continue; 724 } 725 /* We seem to have a node of sorts. Check the CRC */ 726 crcnode.magic = node->magic; 727 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE); 728 crcnode.totlen = node->totlen; 729 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4); 730 731 if (hdr_crc != je32_to_cpu(node->hdr_crc)) { 732 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", 733 ofs, je16_to_cpu(node->magic), 734 je16_to_cpu(node->nodetype), 735 je32_to_cpu(node->totlen), 736 je32_to_cpu(node->hdr_crc), 737 hdr_crc); 738 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 739 return err; 740 ofs += 4; 741 continue; 742 } 743 744 if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) { 745 /* Eep. Node goes over the end of the erase block. */ 746 printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n", 747 ofs, je32_to_cpu(node->totlen)); 748 printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n"); 749 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 750 return err; 751 ofs += 4; 752 continue; 753 } 754 755 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) { 756 /* Wheee. This is an obsoleted node */ 757 D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs)); 758 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 759 return err; 760 ofs += PAD(je32_to_cpu(node->totlen)); 761 continue; 762 } 763 764 switch(je16_to_cpu(node->nodetype)) { 765 case JFFS2_NODETYPE_INODE: 766 if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) { 767 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 768 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n", 769 sizeof(struct jffs2_raw_inode), buf_len, ofs)); 770 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 771 if (err) 772 return err; 773 buf_ofs = ofs; 774 node = (void *)buf; 775 } 776 err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s); 777 if (err) return err; 778 ofs += PAD(je32_to_cpu(node->totlen)); 779 break; 780 781 case JFFS2_NODETYPE_DIRENT: 782 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 783 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 784 D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) 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_dirent_node(c, jeb, (void *)node, ofs, s); 793 if (err) return err; 794 ofs += PAD(je32_to_cpu(node->totlen)); 795 break; 796 797#ifdef CONFIG_JFFS2_FS_XATTR 798 case JFFS2_NODETYPE_XATTR: 799 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 800 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 801 D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)" 802 " left to end of buf. Reading 0x%x at 0x%08x\n", 803 je32_to_cpu(node->totlen), buf_len, ofs)); 804 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 805 if (err) 806 return err; 807 buf_ofs = ofs; 808 node = (void *)buf; 809 } 810 err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s); 811 if (err) 812 return err; 813 ofs += PAD(je32_to_cpu(node->totlen)); 814 break; 815 case JFFS2_NODETYPE_XREF: 816 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 817 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 818 D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)" 819 " left to end of buf. Reading 0x%x at 0x%08x\n", 820 je32_to_cpu(node->totlen), buf_len, ofs)); 821 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 822 if (err) 823 return err; 824 buf_ofs = ofs; 825 node = (void *)buf; 826 } 827 err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s); 828 if (err) 829 return err; 830 ofs += PAD(je32_to_cpu(node->totlen)); 831 break; 832#endif /* CONFIG_JFFS2_FS_XATTR */ 833 834 case JFFS2_NODETYPE_CLEANMARKER: 835 D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs)); 836 if (je32_to_cpu(node->totlen) != c->cleanmarker_size) { 837 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n", 838 ofs, je32_to_cpu(node->totlen), c->cleanmarker_size); 839 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node))))) 840 return err; 841 ofs += PAD(sizeof(struct jffs2_unknown_node)); 842 } else if (jeb->first_node) { 843 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset); 844 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node))))) 845 return err; 846 ofs += PAD(sizeof(struct jffs2_unknown_node)); 847 } else { 848 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL); 849 850 ofs += PAD(c->cleanmarker_size); 851 } 852 break; 853 854 case JFFS2_NODETYPE_PADDING: 855 if (jffs2_sum_active()) 856 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen)); 857 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 858 return err; 859 ofs += PAD(je32_to_cpu(node->totlen)); 860 break; 861 862 default: 863 switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) { 864 case JFFS2_FEATURE_ROCOMPAT: 865 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs); 866 c->flags |= JFFS2_SB_FLAG_RO; 867 if (!(jffs2_is_readonly(c))) 868 return -EROFS; 869 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 870 return err; 871 ofs += PAD(je32_to_cpu(node->totlen)); 872 break; 873 874 case JFFS2_FEATURE_INCOMPAT: 875 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs); 876 return -EINVAL; 877 878 case JFFS2_FEATURE_RWCOMPAT_DELETE: 879 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs)); 880 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 881 return err; 882 ofs += PAD(je32_to_cpu(node->totlen)); 883 break; 884 885 case JFFS2_FEATURE_RWCOMPAT_COPY: { 886 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs)); 887 888 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL); 889 890 /* We can't summarise nodes we don't grok */ 891 jffs2_sum_disable_collecting(s); 892 ofs += PAD(je32_to_cpu(node->totlen)); 893 break; 894 } 895 } 896 } 897 } 898 899 if (jffs2_sum_active()) { 900 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) { 901 dbg_summary("There is not enough space for " 902 "summary information, disabling for this jeb!\n"); 903 jffs2_sum_disable_collecting(s); 904 } 905 } 906 907 D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n", 908 jeb->offset,jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size, jeb->wasted_size)); 909 910 /* mark_node_obsolete can add to wasted !! */ 911 if (jeb->wasted_size) { 912 jeb->dirty_size += jeb->wasted_size; 913 c->dirty_size += jeb->wasted_size; 914 c->wasted_size -= jeb->wasted_size; 915 jeb->wasted_size = 0; 916 } 917 918 return jffs2_scan_classify_jeb(c, jeb); 919} 920 921struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino) 922{ 923 struct jffs2_inode_cache *ic; 924 925 ic = jffs2_get_ino_cache(c, ino); 926 if (ic) 927 return ic; 928 929 if (ino > c->highest_ino) 930 c->highest_ino = ino; 931 932 ic = jffs2_alloc_inode_cache(); 933 if (!ic) { 934 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n"); 935 return NULL; 936 } 937 memset(ic, 0, sizeof(*ic)); 938 939 ic->ino = ino; 940 ic->nodes = (void *)ic; 941 jffs2_add_ino_cache(c, ic); 942 if (ino == 1) 943 ic->nlink = 1; 944 return ic; 945} 946 947static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 948 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s) 949{ 950 struct jffs2_inode_cache *ic; 951 uint32_t crc, ino = je32_to_cpu(ri->ino); 952 953 D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs)); 954 955 /* We do very little here now. Just check the ino# to which we should attribute 956 this node; we can do all the CRC checking etc. later. There's a tradeoff here -- 957 we used to scan the flash once only, reading everything we want from it into 958 memory, then building all our in-core data structures and freeing the extra 959 information. Now we allow the first part of the mount to complete a lot quicker, 960 but we have to go _back_ to the flash in order to finish the CRC checking, etc. 961 Which means that the _full_ amount of time to get to proper write mode with GC 962 operational may actually be _longer_ than before. Sucks to be me. */ 963 964 /* Check the node CRC in any case. */ 965 crc = crc32(0, ri, sizeof(*ri)-8); 966 if (crc != je32_to_cpu(ri->node_crc)) { 967 printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on " 968 "node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 969 ofs, je32_to_cpu(ri->node_crc), crc); 970 /* 971 * We believe totlen because the CRC on the node 972 * _header_ was OK, just the node itself failed. 973 */ 974 return jffs2_scan_dirty_space(c, jeb, 975 PAD(je32_to_cpu(ri->totlen))); 976 } 977 978 ic = jffs2_get_ino_cache(c, ino); 979 if (!ic) { 980 ic = jffs2_scan_make_ino_cache(c, ino); 981 if (!ic) 982 return -ENOMEM; 983 } 984 985 /* Wheee. It worked */ 986 jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic); 987 988 D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n", 989 je32_to_cpu(ri->ino), je32_to_cpu(ri->version), 990 je32_to_cpu(ri->offset), 991 je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize))); 992 993 pseudo_random += je32_to_cpu(ri->version); 994 995 if (jffs2_sum_active()) { 996 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset); 997 } 998 999 return 0; 1000} 1001 1002static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 1003 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s) 1004{ 1005 struct jffs2_full_dirent *fd; 1006 struct jffs2_inode_cache *ic; 1007 uint32_t crc; 1008 int err; 1009 1010 D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs)); 1011 1012 /* We don't get here unless the node is still valid, so we don't have to 1013 mask in the ACCURATE bit any more. */ 1014 crc = crc32(0, rd, sizeof(*rd)-8); 1015 1016 if (crc != je32_to_cpu(rd->node_crc)) { 1017 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1018 ofs, je32_to_cpu(rd->node_crc), crc); 1019 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */ 1020 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen))))) 1021 return err; 1022 return 0; 1023 } 1024 1025 pseudo_random += je32_to_cpu(rd->version); 1026 1027 fd = jffs2_alloc_full_dirent(rd->nsize+1); 1028 if (!fd) { 1029 return -ENOMEM; 1030 } 1031 memcpy(&fd->name, rd->name, rd->nsize); 1032 fd->name[rd->nsize] = 0; 1033 1034 crc = crc32(0, fd->name, rd->nsize); 1035 if (crc != je32_to_cpu(rd->name_crc)) { 1036 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1037 ofs, je32_to_cpu(rd->name_crc), crc); 1038 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino))); 1039 jffs2_free_full_dirent(fd); 1040 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */ 1041 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen))))) 1042 return err; 1043 return 0; 1044 } 1045 ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino)); 1046 if (!ic) { 1047 jffs2_free_full_dirent(fd); 1048 return -ENOMEM; 1049 } 1050 1051 fd->raw = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rd->totlen)), ic); 1052 1053 fd->next = NULL; 1054 fd->version = je32_to_cpu(rd->version); 1055 fd->ino = je32_to_cpu(rd->ino); 1056 fd->nhash = full_name_hash(fd->name, rd->nsize); 1057 fd->type = rd->type; 1058 jffs2_add_fd_to_list(c, fd, &ic->scan_dents); 1059 1060 if (jffs2_sum_active()) { 1061 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset); 1062 } 1063 1064 return 0; 1065} 1066 1067static int count_list(struct list_head *l) 1068{ 1069 uint32_t count = 0; 1070 struct list_head *tmp; 1071 1072 list_for_each(tmp, l) { 1073 count++; 1074 } 1075 return count; 1076} 1077 1078/* Note: This breaks if list_empty(head). I don't care. You 1079 might, if you copy this code and use it elsewhere :) */ 1080static void rotate_list(struct list_head *head, uint32_t count) 1081{ 1082 struct list_head *n = head->next; 1083 1084 list_del(head); 1085 while(count--) { 1086 n = n->next; 1087 } 1088 list_add(head, n); 1089} 1090 1091void jffs2_rotate_lists(struct jffs2_sb_info *c) 1092{ 1093 uint32_t x; 1094 uint32_t rotateby; 1095 1096 x = count_list(&c->clean_list); 1097 if (x) { 1098 rotateby = pseudo_random % x; 1099 rotate_list((&c->clean_list), rotateby); 1100 } 1101 1102 x = count_list(&c->very_dirty_list); 1103 if (x) { 1104 rotateby = pseudo_random % x; 1105 rotate_list((&c->very_dirty_list), rotateby); 1106 } 1107 1108 x = count_list(&c->dirty_list); 1109 if (x) { 1110 rotateby = pseudo_random % x; 1111 rotate_list((&c->dirty_list), rotateby); 1112 } 1113 1114 x = count_list(&c->erasable_list); 1115 if (x) { 1116 rotateby = pseudo_random % x; 1117 rotate_list((&c->erasable_list), rotateby); 1118 } 1119 1120 if (c->nr_erasing_blocks) { 1121 rotateby = pseudo_random % c->nr_erasing_blocks; 1122 rotate_list((&c->erase_pending_list), rotateby); 1123 } 1124 1125 if (c->nr_free_blocks) { 1126 rotateby = pseudo_random % c->nr_free_blocks; 1127 rotate_list((&c->free_list), rotateby); 1128 } 1129} 1130