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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 13 14#include <linux/kernel.h> 15#include <linux/sched.h> 16#include <linux/slab.h> 17#include <linux/mtd/mtd.h> 18#include <linux/pagemap.h> 19#include <linux/crc32.h> 20#include <linux/compiler.h> 21#include "nodelist.h" 22#include "summary.h" 23#include "debug.h" 24 25#define DEFAULT_EMPTY_SCAN_SIZE 256 26 27#define noisy_printk(noise, fmt, ...) \ 28do { \ 29 if (*(noise)) { \ 30 pr_notice(fmt, ##__VA_ARGS__); \ 31 (*(noise))--; \ 32 if (!(*(noise))) \ 33 pr_notice("Further such events for this erase block will not be printed\n"); \ 34 } \ 35} while (0) 36 37static uint32_t pseudo_random; 38 39static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 40 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s); 41 42/* These helper functions _must_ increase ofs and also do the dirty/used space accounting. 43 * Returning an error will abort the mount - bad checksums etc. should just mark the space 44 * as dirty. 45 */ 46static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 47 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s); 48static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 49 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s); 50 51static inline int min_free(struct jffs2_sb_info *c) 52{ 53 uint32_t min = 2 * sizeof(struct jffs2_raw_inode); 54#ifdef CONFIG_JFFS2_FS_WRITEBUFFER 55 if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize) 56 return c->wbuf_pagesize; 57#endif 58 return min; 59 60} 61 62static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) { 63 if (sector_size < DEFAULT_EMPTY_SCAN_SIZE) 64 return sector_size; 65 else 66 return DEFAULT_EMPTY_SCAN_SIZE; 67} 68 69static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb) 70{ 71 int ret; 72 73 if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1))) 74 return ret; 75 if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size))) 76 return ret; 77 /* Turned wasted size into dirty, since we apparently 78 think it's recoverable now. */ 79 jeb->dirty_size += jeb->wasted_size; 80 c->dirty_size += jeb->wasted_size; 81 c->wasted_size -= jeb->wasted_size; 82 jeb->wasted_size = 0; 83 if (VERYDIRTY(c, jeb->dirty_size)) { 84 list_add(&jeb->list, &c->very_dirty_list); 85 } else { 86 list_add(&jeb->list, &c->dirty_list); 87 } 88 return 0; 89} 90 91int jffs2_scan_medium(struct jffs2_sb_info *c) 92{ 93 int i, ret; 94 uint32_t empty_blocks = 0, bad_blocks = 0; 95 unsigned char *flashbuf = NULL; 96 uint32_t buf_size = 0; 97 struct jffs2_summary *s = NULL; /* summary info collected by the scan process */ 98#ifndef __ECOS 99 size_t pointlen, try_size; 100 101 ret = mtd_point(c->mtd, 0, c->mtd->size, &pointlen, 102 (void **)&flashbuf, NULL); 103 if (!ret && pointlen < c->mtd->size) { 104 /* Don't muck about if it won't let us point to the whole flash */ 105 jffs2_dbg(1, "MTD point returned len too short: 0x%zx\n", 106 pointlen); 107 mtd_unpoint(c->mtd, 0, pointlen); 108 flashbuf = NULL; 109 } 110 if (ret && ret != -EOPNOTSUPP) 111 jffs2_dbg(1, "MTD point failed %d\n", ret); 112#endif 113 if (!flashbuf) { 114 /* For NAND it's quicker to read a whole eraseblock at a time, 115 apparently */ 116 if (jffs2_cleanmarker_oob(c)) 117 try_size = c->sector_size; 118 else 119 try_size = PAGE_SIZE; 120 121 jffs2_dbg(1, "Trying to allocate readbuf of %zu " 122 "bytes\n", try_size); 123 124 flashbuf = mtd_kmalloc_up_to(c->mtd, &try_size); 125 if (!flashbuf) 126 return -ENOMEM; 127 128 jffs2_dbg(1, "Allocated readbuf of %zu bytes\n", 129 try_size); 130 131 buf_size = (uint32_t)try_size; 132 } 133 134 if (jffs2_sum_active()) { 135 s = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL); 136 if (!s) { 137 JFFS2_WARNING("Can't allocate memory for summary\n"); 138 ret = -ENOMEM; 139 goto out; 140 } 141 } 142 143 for (i=0; i<c->nr_blocks; i++) { 144 struct jffs2_eraseblock *jeb = &c->blocks[i]; 145 146 cond_resched(); 147 148 /* reset summary info for next eraseblock scan */ 149 jffs2_sum_reset_collected(s); 150 151 ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset), 152 buf_size, s); 153 154 if (ret < 0) 155 goto out; 156 157 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 158 159 /* Now decide which list to put it on */ 160 switch(ret) { 161 case BLK_STATE_ALLFF: 162 /* 163 * Empty block. Since we can't be sure it 164 * was entirely erased, we just queue it for erase 165 * again. It will be marked as such when the erase 166 * is complete. Meanwhile we still count it as empty 167 * for later checks. 168 */ 169 empty_blocks++; 170 list_add(&jeb->list, &c->erase_pending_list); 171 c->nr_erasing_blocks++; 172 break; 173 174 case BLK_STATE_CLEANMARKER: 175 /* Only a CLEANMARKER node is valid */ 176 if (!jeb->dirty_size) { 177 /* It's actually free */ 178 list_add(&jeb->list, &c->free_list); 179 c->nr_free_blocks++; 180 } else { 181 /* Dirt */ 182 jffs2_dbg(1, "Adding all-dirty block at 0x%08x to erase_pending_list\n", 183 jeb->offset); 184 list_add(&jeb->list, &c->erase_pending_list); 185 c->nr_erasing_blocks++; 186 } 187 break; 188 189 case BLK_STATE_CLEAN: 190 /* Full (or almost full) of clean data. Clean list */ 191 list_add(&jeb->list, &c->clean_list); 192 break; 193 194 case BLK_STATE_PARTDIRTY: 195 /* Some data, but not full. Dirty list. */ 196 /* We want to remember the block with most free space 197 and stick it in the 'nextblock' position to start writing to it. */ 198 if (jeb->free_size > min_free(c) && 199 (!c->nextblock || c->nextblock->free_size < jeb->free_size)) { 200 /* Better candidate for the next writes to go to */ 201 if (c->nextblock) { 202 ret = file_dirty(c, c->nextblock); 203 if (ret) 204 goto out; 205 /* deleting summary information of the old nextblock */ 206 jffs2_sum_reset_collected(c->summary); 207 } 208 /* update collected summary information for the current nextblock */ 209 jffs2_sum_move_collected(c, s); 210 jffs2_dbg(1, "%s(): new nextblock = 0x%08x\n", 211 __func__, jeb->offset); 212 c->nextblock = jeb; 213 } else { 214 ret = file_dirty(c, jeb); 215 if (ret) 216 goto out; 217 } 218 break; 219 220 case BLK_STATE_ALLDIRTY: 221 /* Nothing valid - not even a clean marker. Needs erasing. */ 222 /* For now we just put it on the erasing list. We'll start the erases later */ 223 jffs2_dbg(1, "Erase block at 0x%08x is not formatted. It will be erased\n", 224 jeb->offset); 225 list_add(&jeb->list, &c->erase_pending_list); 226 c->nr_erasing_blocks++; 227 break; 228 229 case BLK_STATE_BADBLOCK: 230 jffs2_dbg(1, "Block at 0x%08x is bad\n", jeb->offset); 231 list_add(&jeb->list, &c->bad_list); 232 c->bad_size += c->sector_size; 233 c->free_size -= c->sector_size; 234 bad_blocks++; 235 break; 236 default: 237 pr_warn("%s(): unknown block state\n", __func__); 238 BUG(); 239 } 240 } 241 242 /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */ 243 if (c->nextblock && (c->nextblock->dirty_size)) { 244 c->nextblock->wasted_size += c->nextblock->dirty_size; 245 c->wasted_size += c->nextblock->dirty_size; 246 c->dirty_size -= c->nextblock->dirty_size; 247 c->nextblock->dirty_size = 0; 248 } 249#ifdef CONFIG_JFFS2_FS_WRITEBUFFER 250 if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) { 251 /* If we're going to start writing into a block which already 252 contains data, and the end of the data isn't page-aligned, 253 skip a little and align it. */ 254 255 uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize; 256 257 jffs2_dbg(1, "%s(): Skipping %d bytes in nextblock to ensure page alignment\n", 258 __func__, skip); 259 jffs2_prealloc_raw_node_refs(c, c->nextblock, 1); 260 jffs2_scan_dirty_space(c, c->nextblock, skip); 261 } 262#endif 263 if (c->nr_erasing_blocks) { 264 if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) { 265 pr_notice("Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n"); 266 pr_notice("empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n", 267 empty_blocks, bad_blocks, c->nr_blocks); 268 ret = -EIO; 269 goto out; 270 } 271 spin_lock(&c->erase_completion_lock); 272 jffs2_garbage_collect_trigger(c); 273 spin_unlock(&c->erase_completion_lock); 274 } 275 ret = 0; 276 out: 277 if (buf_size) 278 kfree(flashbuf); 279#ifndef __ECOS 280 else 281 mtd_unpoint(c->mtd, 0, c->mtd->size); 282#endif 283 kfree(s); 284 return ret; 285} 286 287static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf, 288 uint32_t ofs, uint32_t len) 289{ 290 int ret; 291 size_t retlen; 292 293 ret = jffs2_flash_read(c, ofs, len, &retlen, buf); 294 if (ret) { 295 jffs2_dbg(1, "mtd->read(0x%x bytes from 0x%x) returned %d\n", 296 len, ofs, ret); 297 return ret; 298 } 299 if (retlen < len) { 300 jffs2_dbg(1, "Read at 0x%x gave only 0x%zx bytes\n", 301 ofs, retlen); 302 return -EIO; 303 } 304 return 0; 305} 306 307int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb) 308{ 309 if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size 310 && (!jeb->first_node || !ref_next(jeb->first_node)) ) 311 return BLK_STATE_CLEANMARKER; 312 313 /* move blocks with max 4 byte dirty space to cleanlist */ 314 else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) { 315 c->dirty_size -= jeb->dirty_size; 316 c->wasted_size += jeb->dirty_size; 317 jeb->wasted_size += jeb->dirty_size; 318 jeb->dirty_size = 0; 319 return BLK_STATE_CLEAN; 320 } else if (jeb->used_size || jeb->unchecked_size) 321 return BLK_STATE_PARTDIRTY; 322 else 323 return BLK_STATE_ALLDIRTY; 324} 325 326#ifdef CONFIG_JFFS2_FS_XATTR 327static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 328 struct jffs2_raw_xattr *rx, uint32_t ofs, 329 struct jffs2_summary *s) 330{ 331 struct jffs2_xattr_datum *xd; 332 uint32_t xid, version, totlen, crc; 333 int err; 334 335 crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4); 336 if (crc != je32_to_cpu(rx->node_crc)) { 337 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n", 338 ofs, je32_to_cpu(rx->node_crc), crc); 339 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen)))) 340 return err; 341 return 0; 342 } 343 344 xid = je32_to_cpu(rx->xid); 345 version = je32_to_cpu(rx->version); 346 347 totlen = PAD(sizeof(struct jffs2_raw_xattr) 348 + rx->name_len + 1 + je16_to_cpu(rx->value_len)); 349 if (totlen != je32_to_cpu(rx->totlen)) { 350 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n", 351 ofs, je32_to_cpu(rx->totlen), totlen); 352 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen)))) 353 return err; 354 return 0; 355 } 356 357 xd = jffs2_setup_xattr_datum(c, xid, version); 358 if (IS_ERR(xd)) 359 return PTR_ERR(xd); 360 361 if (xd->version > version) { 362 struct jffs2_raw_node_ref *raw 363 = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL); 364 raw->next_in_ino = xd->node->next_in_ino; 365 xd->node->next_in_ino = raw; 366 } else { 367 xd->version = version; 368 xd->xprefix = rx->xprefix; 369 xd->name_len = rx->name_len; 370 xd->value_len = je16_to_cpu(rx->value_len); 371 xd->data_crc = je32_to_cpu(rx->data_crc); 372 373 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd); 374 } 375 376 if (jffs2_sum_active()) 377 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset); 378 dbg_xattr("scanning xdatum at %#08x (xid=%u, version=%u)\n", 379 ofs, xd->xid, xd->version); 380 return 0; 381} 382 383static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 384 struct jffs2_raw_xref *rr, uint32_t ofs, 385 struct jffs2_summary *s) 386{ 387 struct jffs2_xattr_ref *ref; 388 uint32_t crc; 389 int err; 390 391 crc = crc32(0, rr, sizeof(*rr) - 4); 392 if (crc != je32_to_cpu(rr->node_crc)) { 393 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n", 394 ofs, je32_to_cpu(rr->node_crc), crc); 395 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen))))) 396 return err; 397 return 0; 398 } 399 400 if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) { 401 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n", 402 ofs, je32_to_cpu(rr->totlen), 403 PAD(sizeof(struct jffs2_raw_xref))); 404 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen)))) 405 return err; 406 return 0; 407 } 408 409 ref = jffs2_alloc_xattr_ref(); 410 if (!ref) 411 return -ENOMEM; 412 413 /* BEFORE jffs2_build_xattr_subsystem() called, 414 * and AFTER xattr_ref is marked as a dead xref, 415 * ref->xid is used to store 32bit xid, xd is not used 416 * ref->ino is used to store 32bit inode-number, ic is not used 417 * Thoes variables are declared as union, thus using those 418 * are exclusive. In a similar way, ref->next is temporarily 419 * used to chain all xattr_ref object. It's re-chained to 420 * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly. 421 */ 422 ref->ino = je32_to_cpu(rr->ino); 423 ref->xid = je32_to_cpu(rr->xid); 424 ref->xseqno = je32_to_cpu(rr->xseqno); 425 if (ref->xseqno > c->highest_xseqno) 426 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER); 427 ref->next = c->xref_temp; 428 c->xref_temp = ref; 429 430 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref); 431 432 if (jffs2_sum_active()) 433 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset); 434 dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n", 435 ofs, ref->xid, ref->ino); 436 return 0; 437} 438#endif 439 440/* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into 441 the flash, XIP-style */ 442static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 443 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) { 444 struct jffs2_unknown_node *node; 445 struct jffs2_unknown_node crcnode; 446 uint32_t ofs, prevofs, max_ofs; 447 uint32_t hdr_crc, buf_ofs, buf_len; 448 int err; 449 int noise = 0; 450 451 452#ifdef CONFIG_JFFS2_FS_WRITEBUFFER 453 int cleanmarkerfound = 0; 454#endif 455 456 ofs = jeb->offset; 457 prevofs = jeb->offset - 1; 458 459 jffs2_dbg(1, "%s(): Scanning block at 0x%x\n", __func__, ofs); 460 461#ifdef CONFIG_JFFS2_FS_WRITEBUFFER 462 if (jffs2_cleanmarker_oob(c)) { 463 int ret; 464 465 if (mtd_block_isbad(c->mtd, jeb->offset)) 466 return BLK_STATE_BADBLOCK; 467 468 ret = jffs2_check_nand_cleanmarker(c, jeb); 469 jffs2_dbg(2, "jffs_check_nand_cleanmarker returned %d\n", ret); 470 471 /* Even if it's not found, we still scan to see 472 if the block is empty. We use this information 473 to decide whether to erase it or not. */ 474 switch (ret) { 475 case 0: cleanmarkerfound = 1; break; 476 case 1: break; 477 default: return ret; 478 } 479 } 480#endif 481 482 if (jffs2_sum_active()) { 483 struct jffs2_sum_marker *sm; 484 void *sumptr = NULL; 485 uint32_t sumlen; 486 487 if (!buf_size) { 488 /* XIP case. Just look, point at the summary if it's there */ 489 sm = (void *)buf + c->sector_size - sizeof(*sm); 490 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) { 491 sumptr = buf + je32_to_cpu(sm->offset); 492 sumlen = c->sector_size - je32_to_cpu(sm->offset); 493 } 494 } else { 495 /* If NAND flash, read a whole page of it. Else just the end */ 496 if (c->wbuf_pagesize) 497 buf_len = c->wbuf_pagesize; 498 else 499 buf_len = sizeof(*sm); 500 501 /* Read as much as we want into the _end_ of the preallocated buffer */ 502 err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, 503 jeb->offset + c->sector_size - buf_len, 504 buf_len); 505 if (err) 506 return err; 507 508 sm = (void *)buf + buf_size - sizeof(*sm); 509 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) { 510 sumlen = c->sector_size - je32_to_cpu(sm->offset); 511 sumptr = buf + buf_size - sumlen; 512 513 /* sm->offset maybe wrong but MAGIC maybe right */ 514 if (sumlen > c->sector_size) 515 goto full_scan; 516 517 /* Now, make sure the summary itself is available */ 518 if (sumlen > buf_size) { 519 /* Need to kmalloc for this. */ 520 sumptr = kmalloc(sumlen, GFP_KERNEL); 521 if (!sumptr) 522 return -ENOMEM; 523 memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len); 524 } 525 if (buf_len < sumlen) { 526 /* Need to read more so that the entire summary node is present */ 527 err = jffs2_fill_scan_buf(c, sumptr, 528 jeb->offset + c->sector_size - sumlen, 529 sumlen - buf_len); 530 if (err) 531 return err; 532 } 533 } 534 535 } 536 537 if (sumptr) { 538 err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random); 539 540 if (buf_size && sumlen > buf_size) 541 kfree(sumptr); 542 /* If it returns with a real error, bail. 543 If it returns positive, that's a block classification 544 (i.e. BLK_STATE_xxx) so return that too. 545 If it returns zero, fall through to full scan. */ 546 if (err) 547 return err; 548 } 549 } 550 551full_scan: 552 buf_ofs = jeb->offset; 553 554 if (!buf_size) { 555 /* This is the XIP case -- we're reading _directly_ from the flash chip */ 556 buf_len = c->sector_size; 557 } else { 558 buf_len = EMPTY_SCAN_SIZE(c->sector_size); 559 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len); 560 if (err) 561 return err; 562 } 563 564 /* We temporarily use 'ofs' as a pointer into the buffer/jeb */ 565 ofs = 0; 566 max_ofs = EMPTY_SCAN_SIZE(c->sector_size); 567 /* Scan only EMPTY_SCAN_SIZE of 0xFF before declaring it's empty */ 568 while(ofs < max_ofs && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF) 569 ofs += 4; 570 571 if (ofs == max_ofs) { 572#ifdef CONFIG_JFFS2_FS_WRITEBUFFER 573 if (jffs2_cleanmarker_oob(c)) { 574 /* scan oob, take care of cleanmarker */ 575 int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound); 576 jffs2_dbg(2, "jffs2_check_oob_empty returned %d\n", 577 ret); 578 switch (ret) { 579 case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF; 580 case 1: return BLK_STATE_ALLDIRTY; 581 default: return ret; 582 } 583 } 584#endif 585 jffs2_dbg(1, "Block at 0x%08x is empty (erased)\n", 586 jeb->offset); 587 if (c->cleanmarker_size == 0) 588 return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */ 589 else 590 return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */ 591 } 592 if (ofs) { 593 jffs2_dbg(1, "Free space at %08x ends at %08x\n", jeb->offset, 594 jeb->offset + ofs); 595 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1))) 596 return err; 597 if ((err = jffs2_scan_dirty_space(c, jeb, ofs))) 598 return err; 599 } 600 601 /* Now ofs is a complete physical flash offset as it always was... */ 602 ofs += jeb->offset; 603 604 noise = 10; 605 606 dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset); 607 608scan_more: 609 while(ofs < jeb->offset + c->sector_size) { 610 611 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 612 613 /* Make sure there are node refs available for use */ 614 err = jffs2_prealloc_raw_node_refs(c, jeb, 2); 615 if (err) 616 return err; 617 618 cond_resched(); 619 620 if (ofs & 3) { 621 pr_warn("Eep. ofs 0x%08x not word-aligned!\n", ofs); 622 ofs = PAD(ofs); 623 continue; 624 } 625 if (ofs == prevofs) { 626 pr_warn("ofs 0x%08x has already been seen. Skipping\n", 627 ofs); 628 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 629 return err; 630 ofs += 4; 631 continue; 632 } 633 prevofs = ofs; 634 635 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) { 636 jffs2_dbg(1, "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n", 637 sizeof(struct jffs2_unknown_node), 638 jeb->offset, c->sector_size, ofs, 639 sizeof(*node)); 640 if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs))) 641 return err; 642 break; 643 } 644 645 if (buf_ofs + buf_len < ofs + sizeof(*node)) { 646 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 647 jffs2_dbg(1, "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n", 648 sizeof(struct jffs2_unknown_node), 649 buf_len, ofs); 650 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 651 if (err) 652 return err; 653 buf_ofs = ofs; 654 } 655 656 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs]; 657 658 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) { 659 uint32_t inbuf_ofs; 660 uint32_t empty_start, scan_end; 661 662 empty_start = ofs; 663 ofs += 4; 664 scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len); 665 666 jffs2_dbg(1, "Found empty flash at 0x%08x\n", ofs); 667 more_empty: 668 inbuf_ofs = ofs - buf_ofs; 669 while (inbuf_ofs < scan_end) { 670 if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) { 671 pr_warn("Empty flash at 0x%08x ends at 0x%08x\n", 672 empty_start, ofs); 673 if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start))) 674 return err; 675 goto scan_more; 676 } 677 678 inbuf_ofs+=4; 679 ofs += 4; 680 } 681 /* Ran off end. */ 682 jffs2_dbg(1, "Empty flash to end of buffer at 0x%08x\n", 683 ofs); 684 685 /* If we're only checking the beginning of a block with a cleanmarker, 686 bail now */ 687 if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) && 688 c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) { 689 jffs2_dbg(1, "%d bytes at start of block seems clean... assuming all clean\n", 690 EMPTY_SCAN_SIZE(c->sector_size)); 691 return BLK_STATE_CLEANMARKER; 692 } 693 if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */ 694 scan_end = buf_len; 695 goto more_empty; 696 } 697 698 /* See how much more there is to read in this eraseblock... */ 699 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 700 if (!buf_len) { 701 /* No more to read. Break out of main loop without marking 702 this range of empty space as dirty (because it's not) */ 703 jffs2_dbg(1, "Empty flash at %08x runs to end of block. Treating as free_space\n", 704 empty_start); 705 break; 706 } 707 /* point never reaches here */ 708 scan_end = buf_len; 709 jffs2_dbg(1, "Reading another 0x%x at 0x%08x\n", 710 buf_len, ofs); 711 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 712 if (err) 713 return err; 714 buf_ofs = ofs; 715 goto more_empty; 716 } 717 718 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) { 719 pr_warn("Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", 720 ofs); 721 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 722 return err; 723 ofs += 4; 724 continue; 725 } 726 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) { 727 jffs2_dbg(1, "Dirty bitmask at 0x%08x\n", ofs); 728 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 729 return err; 730 ofs += 4; 731 continue; 732 } 733 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) { 734 pr_warn("Old JFFS2 bitmask found at 0x%08x\n", ofs); 735 pr_warn("You cannot use older JFFS2 filesystems with newer kernels\n"); 736 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 737 return err; 738 ofs += 4; 739 continue; 740 } 741 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) { 742 /* OK. We're out of possibilities. Whinge and move on */ 743 noisy_printk(&noise, "%s(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n", 744 __func__, 745 JFFS2_MAGIC_BITMASK, ofs, 746 je16_to_cpu(node->magic)); 747 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 748 return err; 749 ofs += 4; 750 continue; 751 } 752 /* We seem to have a node of sorts. Check the CRC */ 753 crcnode.magic = node->magic; 754 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE); 755 crcnode.totlen = node->totlen; 756 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4); 757 758 if (hdr_crc != je32_to_cpu(node->hdr_crc)) { 759 noisy_printk(&noise, "%s(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n", 760 __func__, 761 ofs, je16_to_cpu(node->magic), 762 je16_to_cpu(node->nodetype), 763 je32_to_cpu(node->totlen), 764 je32_to_cpu(node->hdr_crc), 765 hdr_crc); 766 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 767 return err; 768 ofs += 4; 769 continue; 770 } 771 772 if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) { 773 /* Eep. Node goes over the end of the erase block. */ 774 pr_warn("Node at 0x%08x with length 0x%08x would run over the end of the erase block\n", 775 ofs, je32_to_cpu(node->totlen)); 776 pr_warn("Perhaps the file system was created with the wrong erase size?\n"); 777 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 778 return err; 779 ofs += 4; 780 continue; 781 } 782 783 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) { 784 /* Wheee. This is an obsoleted node */ 785 jffs2_dbg(2, "Node at 0x%08x is obsolete. Skipping\n", 786 ofs); 787 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 788 return err; 789 ofs += PAD(je32_to_cpu(node->totlen)); 790 continue; 791 } 792 793 switch(je16_to_cpu(node->nodetype)) { 794 case JFFS2_NODETYPE_INODE: 795 if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) { 796 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 797 jffs2_dbg(1, "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n", 798 sizeof(struct jffs2_raw_inode), 799 buf_len, ofs); 800 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 801 if (err) 802 return err; 803 buf_ofs = ofs; 804 node = (void *)buf; 805 } 806 err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s); 807 if (err) return err; 808 ofs += PAD(je32_to_cpu(node->totlen)); 809 break; 810 811 case JFFS2_NODETYPE_DIRENT: 812 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 813 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 814 jffs2_dbg(1, "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n", 815 je32_to_cpu(node->totlen), buf_len, 816 ofs); 817 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 818 if (err) 819 return err; 820 buf_ofs = ofs; 821 node = (void *)buf; 822 } 823 err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s); 824 if (err) return err; 825 ofs += PAD(je32_to_cpu(node->totlen)); 826 break; 827 828#ifdef CONFIG_JFFS2_FS_XATTR 829 case JFFS2_NODETYPE_XATTR: 830 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 831 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 832 jffs2_dbg(1, "Fewer than %d bytes (xattr node) left to end of buf. Reading 0x%x at 0x%08x\n", 833 je32_to_cpu(node->totlen), buf_len, 834 ofs); 835 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 836 if (err) 837 return err; 838 buf_ofs = ofs; 839 node = (void *)buf; 840 } 841 err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s); 842 if (err) 843 return err; 844 ofs += PAD(je32_to_cpu(node->totlen)); 845 break; 846 case JFFS2_NODETYPE_XREF: 847 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 848 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 849 jffs2_dbg(1, "Fewer than %d bytes (xref node) left to end of buf. Reading 0x%x at 0x%08x\n", 850 je32_to_cpu(node->totlen), buf_len, 851 ofs); 852 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 853 if (err) 854 return err; 855 buf_ofs = ofs; 856 node = (void *)buf; 857 } 858 err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s); 859 if (err) 860 return err; 861 ofs += PAD(je32_to_cpu(node->totlen)); 862 break; 863#endif /* CONFIG_JFFS2_FS_XATTR */ 864 865 case JFFS2_NODETYPE_CLEANMARKER: 866 jffs2_dbg(1, "CLEANMARKER node found at 0x%08x\n", ofs); 867 if (je32_to_cpu(node->totlen) != c->cleanmarker_size) { 868 pr_notice("CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n", 869 ofs, je32_to_cpu(node->totlen), 870 c->cleanmarker_size); 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 if (jeb->first_node) { 875 pr_notice("CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", 876 ofs, jeb->offset); 877 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node))))) 878 return err; 879 ofs += PAD(sizeof(struct jffs2_unknown_node)); 880 } else { 881 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL); 882 883 ofs += PAD(c->cleanmarker_size); 884 } 885 break; 886 887 case JFFS2_NODETYPE_PADDING: 888 if (jffs2_sum_active()) 889 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen)); 890 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 891 return err; 892 ofs += PAD(je32_to_cpu(node->totlen)); 893 break; 894 895 default: 896 switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) { 897 case JFFS2_FEATURE_ROCOMPAT: 898 pr_notice("Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", 899 je16_to_cpu(node->nodetype), ofs); 900 c->flags |= JFFS2_SB_FLAG_RO; 901 if (!(jffs2_is_readonly(c))) 902 return -EROFS; 903 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 904 return err; 905 ofs += PAD(je32_to_cpu(node->totlen)); 906 break; 907 908 case JFFS2_FEATURE_INCOMPAT: 909 pr_notice("Incompatible feature node (0x%04x) found at offset 0x%08x\n", 910 je16_to_cpu(node->nodetype), ofs); 911 return -EINVAL; 912 913 case JFFS2_FEATURE_RWCOMPAT_DELETE: 914 jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", 915 je16_to_cpu(node->nodetype), ofs); 916 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 917 return err; 918 ofs += PAD(je32_to_cpu(node->totlen)); 919 break; 920 921 case JFFS2_FEATURE_RWCOMPAT_COPY: { 922 jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", 923 je16_to_cpu(node->nodetype), ofs); 924 925 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL); 926 927 /* We can't summarise nodes we don't grok */ 928 jffs2_sum_disable_collecting(s); 929 ofs += PAD(je32_to_cpu(node->totlen)); 930 break; 931 } 932 } 933 } 934 } 935 936 if (jffs2_sum_active()) { 937 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) { 938 dbg_summary("There is not enough space for " 939 "summary information, disabling for this jeb!\n"); 940 jffs2_sum_disable_collecting(s); 941 } 942 } 943 944 jffs2_dbg(1, "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n", 945 jeb->offset, jeb->free_size, jeb->dirty_size, 946 jeb->unchecked_size, jeb->used_size, jeb->wasted_size); 947 948 /* mark_node_obsolete can add to wasted !! */ 949 if (jeb->wasted_size) { 950 jeb->dirty_size += jeb->wasted_size; 951 c->dirty_size += jeb->wasted_size; 952 c->wasted_size -= jeb->wasted_size; 953 jeb->wasted_size = 0; 954 } 955 956 return jffs2_scan_classify_jeb(c, jeb); 957} 958 959struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino) 960{ 961 struct jffs2_inode_cache *ic; 962 963 ic = jffs2_get_ino_cache(c, ino); 964 if (ic) 965 return ic; 966 967 if (ino > c->highest_ino) 968 c->highest_ino = ino; 969 970 ic = jffs2_alloc_inode_cache(); 971 if (!ic) { 972 pr_notice("%s(): allocation of inode cache failed\n", __func__); 973 return NULL; 974 } 975 memset(ic, 0, sizeof(*ic)); 976 977 ic->ino = ino; 978 ic->nodes = (void *)ic; 979 jffs2_add_ino_cache(c, ic); 980 if (ino == 1) 981 ic->pino_nlink = 1; 982 return ic; 983} 984 985static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 986 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s) 987{ 988 struct jffs2_inode_cache *ic; 989 uint32_t crc, ino = je32_to_cpu(ri->ino); 990 991 jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs); 992 993 /* We do very little here now. Just check the ino# to which we should attribute 994 this node; we can do all the CRC checking etc. later. There's a tradeoff here -- 995 we used to scan the flash once only, reading everything we want from it into 996 memory, then building all our in-core data structures and freeing the extra 997 information. Now we allow the first part of the mount to complete a lot quicker, 998 but we have to go _back_ to the flash in order to finish the CRC checking, etc. 999 Which means that the _full_ amount of time to get to proper write mode with GC 1000 operational may actually be _longer_ than before. Sucks to be me. */ 1001 1002 /* Check the node CRC in any case. */ 1003 crc = crc32(0, ri, sizeof(*ri)-8); 1004 if (crc != je32_to_cpu(ri->node_crc)) { 1005 pr_notice("%s(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1006 __func__, ofs, je32_to_cpu(ri->node_crc), crc); 1007 /* 1008 * We believe totlen because the CRC on the node 1009 * _header_ was OK, just the node itself failed. 1010 */ 1011 return jffs2_scan_dirty_space(c, jeb, 1012 PAD(je32_to_cpu(ri->totlen))); 1013 } 1014 1015 ic = jffs2_get_ino_cache(c, ino); 1016 if (!ic) { 1017 ic = jffs2_scan_make_ino_cache(c, ino); 1018 if (!ic) 1019 return -ENOMEM; 1020 } 1021 1022 /* Wheee. It worked */ 1023 jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic); 1024 1025 jffs2_dbg(1, "Node is ino #%u, version %d. Range 0x%x-0x%x\n", 1026 je32_to_cpu(ri->ino), je32_to_cpu(ri->version), 1027 je32_to_cpu(ri->offset), 1028 je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)); 1029 1030 pseudo_random += je32_to_cpu(ri->version); 1031 1032 if (jffs2_sum_active()) { 1033 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset); 1034 } 1035 1036 return 0; 1037} 1038 1039static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 1040 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s) 1041{ 1042 struct jffs2_full_dirent *fd; 1043 struct jffs2_inode_cache *ic; 1044 uint32_t checkedlen; 1045 uint32_t crc; 1046 int err; 1047 1048 jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs); 1049 1050 /* We don't get here unless the node is still valid, so we don't have to 1051 mask in the ACCURATE bit any more. */ 1052 crc = crc32(0, rd, sizeof(*rd)-8); 1053 1054 if (crc != je32_to_cpu(rd->node_crc)) { 1055 pr_notice("%s(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1056 __func__, ofs, je32_to_cpu(rd->node_crc), crc); 1057 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */ 1058 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen))))) 1059 return err; 1060 return 0; 1061 } 1062 1063 pseudo_random += je32_to_cpu(rd->version); 1064 1065 /* Should never happen. Did. (OLPC trac #4184)*/ 1066 checkedlen = strnlen(rd->name, rd->nsize); 1067 if (checkedlen < rd->nsize) { 1068 pr_err("Dirent at %08x has zeroes in name. Truncating to %d chars\n", 1069 ofs, checkedlen); 1070 } 1071 fd = jffs2_alloc_full_dirent(checkedlen+1); 1072 if (!fd) { 1073 return -ENOMEM; 1074 } 1075 memcpy(&fd->name, rd->name, checkedlen); 1076 fd->name[checkedlen] = 0; 1077 1078 crc = crc32(0, fd->name, rd->nsize); 1079 if (crc != je32_to_cpu(rd->name_crc)) { 1080 pr_notice("%s(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1081 __func__, ofs, je32_to_cpu(rd->name_crc), crc); 1082 jffs2_dbg(1, "Name for which CRC failed is (now) '%s', ino #%d\n", 1083 fd->name, je32_to_cpu(rd->ino)); 1084 jffs2_free_full_dirent(fd); 1085 /* FIXME: Why do we believe totlen? */ 1086 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */ 1087 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen))))) 1088 return err; 1089 return 0; 1090 } 1091 ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino)); 1092 if (!ic) { 1093 jffs2_free_full_dirent(fd); 1094 return -ENOMEM; 1095 } 1096 1097 fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd), 1098 PAD(je32_to_cpu(rd->totlen)), ic); 1099 1100 fd->next = NULL; 1101 fd->version = je32_to_cpu(rd->version); 1102 fd->ino = je32_to_cpu(rd->ino); 1103 fd->nhash = full_name_hash(fd->name, checkedlen); 1104 fd->type = rd->type; 1105 jffs2_add_fd_to_list(c, fd, &ic->scan_dents); 1106 1107 if (jffs2_sum_active()) { 1108 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset); 1109 } 1110 1111 return 0; 1112} 1113 1114static int count_list(struct list_head *l) 1115{ 1116 uint32_t count = 0; 1117 struct list_head *tmp; 1118 1119 list_for_each(tmp, l) { 1120 count++; 1121 } 1122 return count; 1123} 1124 1125/* Note: This breaks if list_empty(head). I don't care. You 1126 might, if you copy this code and use it elsewhere :) */ 1127static void rotate_list(struct list_head *head, uint32_t count) 1128{ 1129 struct list_head *n = head->next; 1130 1131 list_del(head); 1132 while(count--) { 1133 n = n->next; 1134 } 1135 list_add(head, n); 1136} 1137 1138void jffs2_rotate_lists(struct jffs2_sb_info *c) 1139{ 1140 uint32_t x; 1141 uint32_t rotateby; 1142 1143 x = count_list(&c->clean_list); 1144 if (x) { 1145 rotateby = pseudo_random % x; 1146 rotate_list((&c->clean_list), rotateby); 1147 } 1148 1149 x = count_list(&c->very_dirty_list); 1150 if (x) { 1151 rotateby = pseudo_random % x; 1152 rotate_list((&c->very_dirty_list), rotateby); 1153 } 1154 1155 x = count_list(&c->dirty_list); 1156 if (x) { 1157 rotateby = pseudo_random % x; 1158 rotate_list((&c->dirty_list), rotateby); 1159 } 1160 1161 x = count_list(&c->erasable_list); 1162 if (x) { 1163 rotateby = pseudo_random % x; 1164 rotate_list((&c->erasable_list), rotateby); 1165 } 1166 1167 if (c->nr_erasing_blocks) { 1168 rotateby = pseudo_random % c->nr_erasing_blocks; 1169 rotate_list((&c->erase_pending_list), rotateby); 1170 } 1171 1172 if (c->nr_free_blocks) { 1173 rotateby = pseudo_random % c->nr_free_blocks; 1174 rotate_list((&c->free_list), rotateby); 1175 } 1176} 1177