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, ...) \ 28 do { \ 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 37 static uint32_t pseudo_random; 38 39 static 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 */ 46 static 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); 48 static 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 51 static 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 62 static 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 69 static 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 91 int 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_buf; 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 ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1); 260 if (ret) 261 goto out; 262 jffs2_scan_dirty_space(c, c->nextblock, skip); 263 } 264 #endif 265 if (c->nr_erasing_blocks) { 266 if (!c->used_size && !c->unchecked_size && 267 ((c->nr_free_blocks+empty_blocks+bad_blocks) != c->nr_blocks || bad_blocks == c->nr_blocks)) { 268 pr_notice("Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n"); 269 pr_notice("empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n", 270 empty_blocks, bad_blocks, c->nr_blocks); 271 ret = -EIO; 272 goto out; 273 } 274 spin_lock(&c->erase_completion_lock); 275 jffs2_garbage_collect_trigger(c); 276 spin_unlock(&c->erase_completion_lock); 277 } 278 ret = 0; 279 out: 280 jffs2_sum_reset_collected(s); 281 kfree(s); 282 out_buf: 283 if (buf_size) 284 kfree(flashbuf); 285 #ifndef __ECOS 286 else 287 mtd_unpoint(c->mtd, 0, c->mtd->size); 288 #endif 289 return ret; 290 } 291 292 static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf, 293 uint32_t ofs, uint32_t len) 294 { 295 int ret; 296 size_t retlen; 297 298 ret = jffs2_flash_read(c, ofs, len, &retlen, buf); 299 if (ret) { 300 jffs2_dbg(1, "mtd->read(0x%x bytes from 0x%x) returned %d\n", 301 len, ofs, ret); 302 return ret; 303 } 304 if (retlen < len) { 305 jffs2_dbg(1, "Read at 0x%x gave only 0x%zx bytes\n", 306 ofs, retlen); 307 return -EIO; 308 } 309 return 0; 310 } 311 312 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb) 313 { 314 if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size 315 && (!jeb->first_node || !ref_next(jeb->first_node)) ) 316 return BLK_STATE_CLEANMARKER; 317 318 /* move blocks with max 4 byte dirty space to cleanlist */ 319 else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) { 320 c->dirty_size -= jeb->dirty_size; 321 c->wasted_size += jeb->dirty_size; 322 jeb->wasted_size += jeb->dirty_size; 323 jeb->dirty_size = 0; 324 return BLK_STATE_CLEAN; 325 } else if (jeb->used_size || jeb->unchecked_size) 326 return BLK_STATE_PARTDIRTY; 327 else 328 return BLK_STATE_ALLDIRTY; 329 } 330 331 #ifdef CONFIG_JFFS2_FS_XATTR 332 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 333 struct jffs2_raw_xattr *rx, uint32_t ofs, 334 struct jffs2_summary *s) 335 { 336 struct jffs2_xattr_datum *xd; 337 uint32_t xid, version, totlen, crc; 338 int err; 339 340 crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4); 341 if (crc != je32_to_cpu(rx->node_crc)) { 342 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n", 343 ofs, je32_to_cpu(rx->node_crc), crc); 344 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen)))) 345 return err; 346 return 0; 347 } 348 349 xid = je32_to_cpu(rx->xid); 350 version = je32_to_cpu(rx->version); 351 352 totlen = PAD(sizeof(struct jffs2_raw_xattr) 353 + rx->name_len + 1 + je16_to_cpu(rx->value_len)); 354 if (totlen != je32_to_cpu(rx->totlen)) { 355 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n", 356 ofs, je32_to_cpu(rx->totlen), totlen); 357 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen)))) 358 return err; 359 return 0; 360 } 361 362 xd = jffs2_setup_xattr_datum(c, xid, version); 363 if (IS_ERR(xd)) 364 return PTR_ERR(xd); 365 366 if (xd->version > version) { 367 struct jffs2_raw_node_ref *raw 368 = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL); 369 raw->next_in_ino = xd->node->next_in_ino; 370 xd->node->next_in_ino = raw; 371 } else { 372 xd->version = version; 373 xd->xprefix = rx->xprefix; 374 xd->name_len = rx->name_len; 375 xd->value_len = je16_to_cpu(rx->value_len); 376 xd->data_crc = je32_to_cpu(rx->data_crc); 377 378 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd); 379 } 380 381 if (jffs2_sum_active()) 382 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset); 383 dbg_xattr("scanning xdatum at %#08x (xid=%u, version=%u)\n", 384 ofs, xd->xid, xd->version); 385 return 0; 386 } 387 388 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 389 struct jffs2_raw_xref *rr, uint32_t ofs, 390 struct jffs2_summary *s) 391 { 392 struct jffs2_xattr_ref *ref; 393 uint32_t crc; 394 int err; 395 396 crc = crc32(0, rr, sizeof(*rr) - 4); 397 if (crc != je32_to_cpu(rr->node_crc)) { 398 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n", 399 ofs, je32_to_cpu(rr->node_crc), crc); 400 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen))))) 401 return err; 402 return 0; 403 } 404 405 if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) { 406 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n", 407 ofs, je32_to_cpu(rr->totlen), 408 PAD(sizeof(struct jffs2_raw_xref))); 409 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen)))) 410 return err; 411 return 0; 412 } 413 414 ref = jffs2_alloc_xattr_ref(); 415 if (!ref) 416 return -ENOMEM; 417 418 /* BEFORE jffs2_build_xattr_subsystem() called, 419 * and AFTER xattr_ref is marked as a dead xref, 420 * ref->xid is used to store 32bit xid, xd is not used 421 * ref->ino is used to store 32bit inode-number, ic is not used 422 * Thoes variables are declared as union, thus using those 423 * are exclusive. In a similar way, ref->next is temporarily 424 * used to chain all xattr_ref object. It's re-chained to 425 * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly. 426 */ 427 ref->ino = je32_to_cpu(rr->ino); 428 ref->xid = je32_to_cpu(rr->xid); 429 ref->xseqno = je32_to_cpu(rr->xseqno); 430 if (ref->xseqno > c->highest_xseqno) 431 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER); 432 ref->next = c->xref_temp; 433 c->xref_temp = ref; 434 435 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref); 436 437 if (jffs2_sum_active()) 438 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset); 439 dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n", 440 ofs, ref->xid, ref->ino); 441 return 0; 442 } 443 #endif 444 445 /* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into 446 the flash, XIP-style */ 447 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 448 unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) { 449 struct jffs2_unknown_node *node; 450 struct jffs2_unknown_node crcnode; 451 uint32_t ofs, prevofs, max_ofs; 452 uint32_t hdr_crc, buf_ofs, buf_len; 453 int err; 454 int noise = 0; 455 456 457 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 458 int cleanmarkerfound = 0; 459 #endif 460 461 ofs = jeb->offset; 462 prevofs = jeb->offset - 1; 463 464 jffs2_dbg(1, "%s(): Scanning block at 0x%x\n", __func__, ofs); 465 466 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 467 if (jffs2_cleanmarker_oob(c)) { 468 int ret; 469 470 if (mtd_block_isbad(c->mtd, jeb->offset)) 471 return BLK_STATE_BADBLOCK; 472 473 ret = jffs2_check_nand_cleanmarker(c, jeb); 474 jffs2_dbg(2, "jffs_check_nand_cleanmarker returned %d\n", ret); 475 476 /* Even if it's not found, we still scan to see 477 if the block is empty. We use this information 478 to decide whether to erase it or not. */ 479 switch (ret) { 480 case 0: cleanmarkerfound = 1; break; 481 case 1: break; 482 default: return ret; 483 } 484 } 485 #endif 486 487 if (jffs2_sum_active()) { 488 struct jffs2_sum_marker *sm; 489 void *sumptr = NULL; 490 uint32_t sumlen; 491 492 if (!buf_size) { 493 /* XIP case. Just look, point at the summary if it's there */ 494 sm = (void *)buf + c->sector_size - sizeof(*sm); 495 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) { 496 sumptr = buf + je32_to_cpu(sm->offset); 497 sumlen = c->sector_size - je32_to_cpu(sm->offset); 498 } 499 } else { 500 /* If NAND flash, read a whole page of it. Else just the end */ 501 if (c->wbuf_pagesize) 502 buf_len = c->wbuf_pagesize; 503 else 504 buf_len = sizeof(*sm); 505 506 /* Read as much as we want into the _end_ of the preallocated buffer */ 507 err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, 508 jeb->offset + c->sector_size - buf_len, 509 buf_len); 510 if (err) 511 return err; 512 513 sm = (void *)buf + buf_size - sizeof(*sm); 514 if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) { 515 sumlen = c->sector_size - je32_to_cpu(sm->offset); 516 sumptr = buf + buf_size - sumlen; 517 518 /* sm->offset maybe wrong but MAGIC maybe right */ 519 if (sumlen > c->sector_size) 520 goto full_scan; 521 522 /* Now, make sure the summary itself is available */ 523 if (sumlen > buf_size) { 524 /* Need to kmalloc for this. */ 525 sumptr = kmalloc(sumlen, GFP_KERNEL); 526 if (!sumptr) 527 return -ENOMEM; 528 memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len); 529 } 530 if (buf_len < sumlen) { 531 /* Need to read more so that the entire summary node is present */ 532 err = jffs2_fill_scan_buf(c, sumptr, 533 jeb->offset + c->sector_size - sumlen, 534 sumlen - buf_len); 535 if (err) { 536 if (sumlen > buf_size) 537 kfree(sumptr); 538 return err; 539 } 540 } 541 } 542 543 } 544 545 if (sumptr) { 546 err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random); 547 548 if (buf_size && sumlen > buf_size) 549 kfree(sumptr); 550 /* If it returns with a real error, bail. 551 If it returns positive, that's a block classification 552 (i.e. BLK_STATE_xxx) so return that too. 553 If it returns zero, fall through to full scan. */ 554 if (err) 555 return err; 556 } 557 } 558 559 full_scan: 560 buf_ofs = jeb->offset; 561 562 if (!buf_size) { 563 /* This is the XIP case -- we're reading _directly_ from the flash chip */ 564 buf_len = c->sector_size; 565 } else { 566 buf_len = EMPTY_SCAN_SIZE(c->sector_size); 567 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len); 568 if (err) 569 return err; 570 } 571 572 /* We temporarily use 'ofs' as a pointer into the buffer/jeb */ 573 ofs = 0; 574 max_ofs = EMPTY_SCAN_SIZE(c->sector_size); 575 /* Scan only EMPTY_SCAN_SIZE of 0xFF before declaring it's empty */ 576 while(ofs < max_ofs && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF) 577 ofs += 4; 578 579 if (ofs == max_ofs) { 580 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 581 if (jffs2_cleanmarker_oob(c)) { 582 /* scan oob, take care of cleanmarker */ 583 int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound); 584 jffs2_dbg(2, "jffs2_check_oob_empty returned %d\n", 585 ret); 586 switch (ret) { 587 case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF; 588 case 1: return BLK_STATE_ALLDIRTY; 589 default: return ret; 590 } 591 } 592 #endif 593 jffs2_dbg(1, "Block at 0x%08x is empty (erased)\n", 594 jeb->offset); 595 if (c->cleanmarker_size == 0) 596 return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */ 597 else 598 return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */ 599 } 600 if (ofs) { 601 jffs2_dbg(1, "Free space at %08x ends at %08x\n", jeb->offset, 602 jeb->offset + ofs); 603 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1))) 604 return err; 605 if ((err = jffs2_scan_dirty_space(c, jeb, ofs))) 606 return err; 607 } 608 609 /* Now ofs is a complete physical flash offset as it always was... */ 610 ofs += jeb->offset; 611 612 noise = 10; 613 614 dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset); 615 616 scan_more: 617 while(ofs < jeb->offset + c->sector_size) { 618 619 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 620 621 /* Make sure there are node refs available for use */ 622 err = jffs2_prealloc_raw_node_refs(c, jeb, 2); 623 if (err) 624 return err; 625 626 cond_resched(); 627 628 if (ofs & 3) { 629 pr_warn("Eep. ofs 0x%08x not word-aligned!\n", ofs); 630 ofs = PAD(ofs); 631 continue; 632 } 633 if (ofs == prevofs) { 634 pr_warn("ofs 0x%08x has already been seen. Skipping\n", 635 ofs); 636 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 637 return err; 638 ofs += 4; 639 continue; 640 } 641 prevofs = ofs; 642 643 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) { 644 jffs2_dbg(1, "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n", 645 sizeof(struct jffs2_unknown_node), 646 jeb->offset, c->sector_size, ofs, 647 sizeof(*node)); 648 if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs))) 649 return err; 650 break; 651 } 652 653 if (buf_ofs + buf_len < ofs + sizeof(*node)) { 654 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 655 jffs2_dbg(1, "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n", 656 sizeof(struct jffs2_unknown_node), 657 buf_len, ofs); 658 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 659 if (err) 660 return err; 661 buf_ofs = ofs; 662 } 663 664 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs]; 665 666 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) { 667 uint32_t inbuf_ofs; 668 uint32_t empty_start, scan_end; 669 670 empty_start = ofs; 671 ofs += 4; 672 scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len); 673 674 jffs2_dbg(1, "Found empty flash at 0x%08x\n", ofs); 675 more_empty: 676 inbuf_ofs = ofs - buf_ofs; 677 while (inbuf_ofs < scan_end) { 678 if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) { 679 pr_warn("Empty flash at 0x%08x ends at 0x%08x\n", 680 empty_start, ofs); 681 if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start))) 682 return err; 683 goto scan_more; 684 } 685 686 inbuf_ofs+=4; 687 ofs += 4; 688 } 689 /* Ran off end. */ 690 jffs2_dbg(1, "Empty flash to end of buffer at 0x%08x\n", 691 ofs); 692 693 /* If we're only checking the beginning of a block with a cleanmarker, 694 bail now */ 695 if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) && 696 c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) { 697 jffs2_dbg(1, "%d bytes at start of block seems clean... assuming all clean\n", 698 EMPTY_SCAN_SIZE(c->sector_size)); 699 return BLK_STATE_CLEANMARKER; 700 } 701 if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */ 702 scan_end = buf_len; 703 goto more_empty; 704 } 705 706 /* See how much more there is to read in this eraseblock... */ 707 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 708 if (!buf_len) { 709 /* No more to read. Break out of main loop without marking 710 this range of empty space as dirty (because it's not) */ 711 jffs2_dbg(1, "Empty flash at %08x runs to end of block. Treating as free_space\n", 712 empty_start); 713 break; 714 } 715 /* point never reaches here */ 716 scan_end = buf_len; 717 jffs2_dbg(1, "Reading another 0x%x at 0x%08x\n", 718 buf_len, ofs); 719 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 720 if (err) 721 return err; 722 buf_ofs = ofs; 723 goto more_empty; 724 } 725 726 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) { 727 pr_warn("Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", 728 ofs); 729 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 730 return err; 731 ofs += 4; 732 continue; 733 } 734 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) { 735 jffs2_dbg(1, "Dirty bitmask at 0x%08x\n", ofs); 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_OLD_MAGIC_BITMASK) { 742 pr_warn("Old JFFS2 bitmask found at 0x%08x\n", ofs); 743 pr_warn("You cannot use older JFFS2 filesystems with newer kernels\n"); 744 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 745 return err; 746 ofs += 4; 747 continue; 748 } 749 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) { 750 /* OK. We're out of possibilities. Whinge and move on */ 751 noisy_printk(&noise, "%s(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n", 752 __func__, 753 JFFS2_MAGIC_BITMASK, ofs, 754 je16_to_cpu(node->magic)); 755 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 756 return err; 757 ofs += 4; 758 continue; 759 } 760 /* We seem to have a node of sorts. Check the CRC */ 761 crcnode.magic = node->magic; 762 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE); 763 crcnode.totlen = node->totlen; 764 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4); 765 766 if (hdr_crc != je32_to_cpu(node->hdr_crc)) { 767 noisy_printk(&noise, "%s(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n", 768 __func__, 769 ofs, je16_to_cpu(node->magic), 770 je16_to_cpu(node->nodetype), 771 je32_to_cpu(node->totlen), 772 je32_to_cpu(node->hdr_crc), 773 hdr_crc); 774 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 775 return err; 776 ofs += 4; 777 continue; 778 } 779 780 if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) { 781 /* Eep. Node goes over the end of the erase block. */ 782 pr_warn("Node at 0x%08x with length 0x%08x would run over the end of the erase block\n", 783 ofs, je32_to_cpu(node->totlen)); 784 pr_warn("Perhaps the file system was created with the wrong erase size?\n"); 785 if ((err = jffs2_scan_dirty_space(c, jeb, 4))) 786 return err; 787 ofs += 4; 788 continue; 789 } 790 791 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) { 792 /* Wheee. This is an obsoleted node */ 793 jffs2_dbg(2, "Node at 0x%08x is obsolete. Skipping\n", 794 ofs); 795 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 796 return err; 797 ofs += PAD(je32_to_cpu(node->totlen)); 798 continue; 799 } 800 801 switch(je16_to_cpu(node->nodetype)) { 802 case JFFS2_NODETYPE_INODE: 803 if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) { 804 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 805 jffs2_dbg(1, "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n", 806 sizeof(struct jffs2_raw_inode), 807 buf_len, ofs); 808 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 809 if (err) 810 return err; 811 buf_ofs = ofs; 812 node = (void *)buf; 813 } 814 err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s); 815 if (err) return err; 816 ofs += PAD(je32_to_cpu(node->totlen)); 817 break; 818 819 case JFFS2_NODETYPE_DIRENT: 820 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 821 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 822 jffs2_dbg(1, "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n", 823 je32_to_cpu(node->totlen), buf_len, 824 ofs); 825 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 826 if (err) 827 return err; 828 buf_ofs = ofs; 829 node = (void *)buf; 830 } 831 err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s); 832 if (err) return err; 833 ofs += PAD(je32_to_cpu(node->totlen)); 834 break; 835 836 #ifdef CONFIG_JFFS2_FS_XATTR 837 case JFFS2_NODETYPE_XATTR: 838 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 839 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 840 jffs2_dbg(1, "Fewer than %d bytes (xattr node) left to end of buf. Reading 0x%x at 0x%08x\n", 841 je32_to_cpu(node->totlen), buf_len, 842 ofs); 843 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 844 if (err) 845 return err; 846 buf_ofs = ofs; 847 node = (void *)buf; 848 } 849 err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s); 850 if (err) 851 return err; 852 ofs += PAD(je32_to_cpu(node->totlen)); 853 break; 854 case JFFS2_NODETYPE_XREF: 855 if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { 856 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); 857 jffs2_dbg(1, "Fewer than %d bytes (xref node) left to end of buf. Reading 0x%x at 0x%08x\n", 858 je32_to_cpu(node->totlen), buf_len, 859 ofs); 860 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); 861 if (err) 862 return err; 863 buf_ofs = ofs; 864 node = (void *)buf; 865 } 866 err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s); 867 if (err) 868 return err; 869 ofs += PAD(je32_to_cpu(node->totlen)); 870 break; 871 #endif /* CONFIG_JFFS2_FS_XATTR */ 872 873 case JFFS2_NODETYPE_CLEANMARKER: 874 jffs2_dbg(1, "CLEANMARKER node found at 0x%08x\n", ofs); 875 if (je32_to_cpu(node->totlen) != c->cleanmarker_size) { 876 pr_notice("CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n", 877 ofs, je32_to_cpu(node->totlen), 878 c->cleanmarker_size); 879 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node))))) 880 return err; 881 ofs += PAD(sizeof(struct jffs2_unknown_node)); 882 } else if (jeb->first_node) { 883 pr_notice("CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", 884 ofs, jeb->offset); 885 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node))))) 886 return err; 887 ofs += PAD(sizeof(struct jffs2_unknown_node)); 888 } else { 889 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL); 890 891 ofs += PAD(c->cleanmarker_size); 892 } 893 break; 894 895 case JFFS2_NODETYPE_PADDING: 896 if (jffs2_sum_active()) 897 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen)); 898 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 899 return err; 900 ofs += PAD(je32_to_cpu(node->totlen)); 901 break; 902 903 default: 904 switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) { 905 case JFFS2_FEATURE_ROCOMPAT: 906 pr_notice("Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", 907 je16_to_cpu(node->nodetype), ofs); 908 c->flags |= JFFS2_SB_FLAG_RO; 909 if (!(jffs2_is_readonly(c))) 910 return -EROFS; 911 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 912 return err; 913 ofs += PAD(je32_to_cpu(node->totlen)); 914 break; 915 916 case JFFS2_FEATURE_INCOMPAT: 917 pr_notice("Incompatible feature node (0x%04x) found at offset 0x%08x\n", 918 je16_to_cpu(node->nodetype), ofs); 919 return -EINVAL; 920 921 case JFFS2_FEATURE_RWCOMPAT_DELETE: 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 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) 925 return err; 926 ofs += PAD(je32_to_cpu(node->totlen)); 927 break; 928 929 case JFFS2_FEATURE_RWCOMPAT_COPY: { 930 jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", 931 je16_to_cpu(node->nodetype), ofs); 932 933 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL); 934 935 /* We can't summarise nodes we don't grok */ 936 jffs2_sum_disable_collecting(s); 937 ofs += PAD(je32_to_cpu(node->totlen)); 938 break; 939 } 940 } 941 } 942 } 943 944 if (jffs2_sum_active()) { 945 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) { 946 dbg_summary("There is not enough space for " 947 "summary information, disabling for this jeb!\n"); 948 jffs2_sum_disable_collecting(s); 949 } 950 } 951 952 jffs2_dbg(1, "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n", 953 jeb->offset, jeb->free_size, jeb->dirty_size, 954 jeb->unchecked_size, jeb->used_size, jeb->wasted_size); 955 956 /* mark_node_obsolete can add to wasted !! */ 957 if (jeb->wasted_size) { 958 jeb->dirty_size += jeb->wasted_size; 959 c->dirty_size += jeb->wasted_size; 960 c->wasted_size -= jeb->wasted_size; 961 jeb->wasted_size = 0; 962 } 963 964 return jffs2_scan_classify_jeb(c, jeb); 965 } 966 967 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino) 968 { 969 struct jffs2_inode_cache *ic; 970 971 ic = jffs2_get_ino_cache(c, ino); 972 if (ic) 973 return ic; 974 975 if (ino > c->highest_ino) 976 c->highest_ino = ino; 977 978 ic = jffs2_alloc_inode_cache(); 979 if (!ic) { 980 pr_notice("%s(): allocation of inode cache failed\n", __func__); 981 return NULL; 982 } 983 memset(ic, 0, sizeof(*ic)); 984 985 ic->ino = ino; 986 ic->nodes = (void *)ic; 987 jffs2_add_ino_cache(c, ic); 988 if (ino == 1) 989 ic->pino_nlink = 1; 990 return ic; 991 } 992 993 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 994 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s) 995 { 996 struct jffs2_inode_cache *ic; 997 uint32_t crc, ino = je32_to_cpu(ri->ino); 998 999 jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs); 1000 1001 /* We do very little here now. Just check the ino# to which we should attribute 1002 this node; we can do all the CRC checking etc. later. There's a tradeoff here -- 1003 we used to scan the flash once only, reading everything we want from it into 1004 memory, then building all our in-core data structures and freeing the extra 1005 information. Now we allow the first part of the mount to complete a lot quicker, 1006 but we have to go _back_ to the flash in order to finish the CRC checking, etc. 1007 Which means that the _full_ amount of time to get to proper write mode with GC 1008 operational may actually be _longer_ than before. Sucks to be me. */ 1009 1010 /* Check the node CRC in any case. */ 1011 crc = crc32(0, ri, sizeof(*ri)-8); 1012 if (crc != je32_to_cpu(ri->node_crc)) { 1013 pr_notice("%s(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1014 __func__, ofs, je32_to_cpu(ri->node_crc), crc); 1015 /* 1016 * We believe totlen because the CRC on the node 1017 * _header_ was OK, just the node itself failed. 1018 */ 1019 return jffs2_scan_dirty_space(c, jeb, 1020 PAD(je32_to_cpu(ri->totlen))); 1021 } 1022 1023 ic = jffs2_get_ino_cache(c, ino); 1024 if (!ic) { 1025 ic = jffs2_scan_make_ino_cache(c, ino); 1026 if (!ic) 1027 return -ENOMEM; 1028 } 1029 1030 /* Wheee. It worked */ 1031 jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic); 1032 1033 jffs2_dbg(1, "Node is ino #%u, version %d. Range 0x%x-0x%x\n", 1034 je32_to_cpu(ri->ino), je32_to_cpu(ri->version), 1035 je32_to_cpu(ri->offset), 1036 je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)); 1037 1038 pseudo_random += je32_to_cpu(ri->version); 1039 1040 if (jffs2_sum_active()) { 1041 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset); 1042 } 1043 1044 return 0; 1045 } 1046 1047 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 1048 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s) 1049 { 1050 struct jffs2_full_dirent *fd; 1051 struct jffs2_inode_cache *ic; 1052 uint32_t checkedlen; 1053 uint32_t crc; 1054 int err; 1055 1056 jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs); 1057 1058 /* We don't get here unless the node is still valid, so we don't have to 1059 mask in the ACCURATE bit any more. */ 1060 crc = crc32(0, rd, sizeof(*rd)-8); 1061 1062 if (crc != je32_to_cpu(rd->node_crc)) { 1063 pr_notice("%s(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1064 __func__, ofs, je32_to_cpu(rd->node_crc), crc); 1065 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */ 1066 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen))))) 1067 return err; 1068 return 0; 1069 } 1070 1071 pseudo_random += je32_to_cpu(rd->version); 1072 1073 /* Should never happen. Did. (OLPC trac #4184)*/ 1074 checkedlen = strnlen(rd->name, rd->nsize); 1075 if (checkedlen < rd->nsize) { 1076 pr_err("Dirent at %08x has zeroes in name. Truncating to %d chars\n", 1077 ofs, checkedlen); 1078 } 1079 fd = jffs2_alloc_full_dirent(checkedlen+1); 1080 if (!fd) { 1081 return -ENOMEM; 1082 } 1083 memcpy(&fd->name, rd->name, checkedlen); 1084 fd->name[checkedlen] = 0; 1085 1086 crc = crc32(0, fd->name, checkedlen); 1087 if (crc != je32_to_cpu(rd->name_crc)) { 1088 pr_notice("%s(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", 1089 __func__, ofs, je32_to_cpu(rd->name_crc), crc); 1090 jffs2_dbg(1, "Name for which CRC failed is (now) '%s', ino #%d\n", 1091 fd->name, je32_to_cpu(rd->ino)); 1092 jffs2_free_full_dirent(fd); 1093 /* FIXME: Why do we believe totlen? */ 1094 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */ 1095 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen))))) 1096 return err; 1097 return 0; 1098 } 1099 ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino)); 1100 if (!ic) { 1101 jffs2_free_full_dirent(fd); 1102 return -ENOMEM; 1103 } 1104 1105 fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd), 1106 PAD(je32_to_cpu(rd->totlen)), ic); 1107 1108 fd->next = NULL; 1109 fd->version = je32_to_cpu(rd->version); 1110 fd->ino = je32_to_cpu(rd->ino); 1111 fd->nhash = full_name_hash(NULL, fd->name, checkedlen); 1112 fd->type = rd->type; 1113 jffs2_add_fd_to_list(c, fd, &ic->scan_dents); 1114 1115 if (jffs2_sum_active()) { 1116 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset); 1117 } 1118 1119 return 0; 1120 } 1121 1122 static int count_list(struct list_head *l) 1123 { 1124 uint32_t count = 0; 1125 struct list_head *tmp; 1126 1127 list_for_each(tmp, l) { 1128 count++; 1129 } 1130 return count; 1131 } 1132 1133 /* Note: This breaks if list_empty(head). I don't care. You 1134 might, if you copy this code and use it elsewhere :) */ 1135 static void rotate_list(struct list_head *head, uint32_t count) 1136 { 1137 struct list_head *n = head->next; 1138 1139 list_del(head); 1140 while(count--) { 1141 n = n->next; 1142 } 1143 list_add(head, n); 1144 } 1145 1146 void jffs2_rotate_lists(struct jffs2_sb_info *c) 1147 { 1148 uint32_t x; 1149 uint32_t rotateby; 1150 1151 x = count_list(&c->clean_list); 1152 if (x) { 1153 rotateby = pseudo_random % x; 1154 rotate_list((&c->clean_list), rotateby); 1155 } 1156 1157 x = count_list(&c->very_dirty_list); 1158 if (x) { 1159 rotateby = pseudo_random % x; 1160 rotate_list((&c->very_dirty_list), rotateby); 1161 } 1162 1163 x = count_list(&c->dirty_list); 1164 if (x) { 1165 rotateby = pseudo_random % x; 1166 rotate_list((&c->dirty_list), rotateby); 1167 } 1168 1169 x = count_list(&c->erasable_list); 1170 if (x) { 1171 rotateby = pseudo_random % x; 1172 rotate_list((&c->erasable_list), rotateby); 1173 } 1174 1175 if (c->nr_erasing_blocks) { 1176 rotateby = pseudo_random % c->nr_erasing_blocks; 1177 rotate_list((&c->erase_pending_list), rotateby); 1178 } 1179 1180 if (c->nr_free_blocks) { 1181 rotateby = pseudo_random % c->nr_free_blocks; 1182 rotate_list((&c->free_list), rotateby); 1183 } 1184 } 1185