1 /* 2 * Copyright (c) International Business Machines Corp., 2006 3 * Copyright (c) Nokia Corporation, 2006, 2007 4 * 5 * SPDX-License-Identifier: GPL-2.0+ 6 * 7 * Author: Artem Bityutskiy (Битюцкий Артём) 8 */ 9 10 /* 11 * This file includes volume table manipulation code. The volume table is an 12 * on-flash table containing volume meta-data like name, number of reserved 13 * physical eraseblocks, type, etc. The volume table is stored in the so-called 14 * "layout volume". 15 * 16 * The layout volume is an internal volume which is organized as follows. It 17 * consists of two logical eraseblocks - LEB 0 and LEB 1. Each logical 18 * eraseblock stores one volume table copy, i.e. LEB 0 and LEB 1 duplicate each 19 * other. This redundancy guarantees robustness to unclean reboots. The volume 20 * table is basically an array of volume table records. Each record contains 21 * full information about the volume and protected by a CRC checksum. 22 * 23 * The volume table is changed, it is first changed in RAM. Then LEB 0 is 24 * erased, and the updated volume table is written back to LEB 0. Then same for 25 * LEB 1. This scheme guarantees recoverability from unclean reboots. 26 * 27 * In this UBI implementation the on-flash volume table does not contain any 28 * information about how much data static volumes contain. 29 * 30 * But it would still be beneficial to store this information in the volume 31 * table. For example, suppose we have a static volume X, and all its physical 32 * eraseblocks became bad for some reasons. Suppose we are attaching the 33 * corresponding MTD device, for some reason we find no logical eraseblocks 34 * corresponding to the volume X. According to the volume table volume X does 35 * exist. So we don't know whether it is just empty or all its physical 36 * eraseblocks went bad. So we cannot alarm the user properly. 37 * 38 * The volume table also stores so-called "update marker", which is used for 39 * volume updates. Before updating the volume, the update marker is set, and 40 * after the update operation is finished, the update marker is cleared. So if 41 * the update operation was interrupted (e.g. by an unclean reboot) - the 42 * update marker is still there and we know that the volume's contents is 43 * damaged. 44 */ 45 46 #define __UBOOT__ 47 #ifndef __UBOOT__ 48 #include <linux/crc32.h> 49 #include <linux/err.h> 50 #include <linux/slab.h> 51 #include <asm/div64.h> 52 #else 53 #include <ubi_uboot.h> 54 #endif 55 56 #include <linux/err.h> 57 #include "ubi.h" 58 59 static void self_vtbl_check(const struct ubi_device *ubi); 60 61 /* Empty volume table record */ 62 static struct ubi_vtbl_record empty_vtbl_record; 63 64 /** 65 * ubi_change_vtbl_record - change volume table record. 66 * @ubi: UBI device description object 67 * @idx: table index to change 68 * @vtbl_rec: new volume table record 69 * 70 * This function changes volume table record @idx. If @vtbl_rec is %NULL, empty 71 * volume table record is written. The caller does not have to calculate CRC of 72 * the record as it is done by this function. Returns zero in case of success 73 * and a negative error code in case of failure. 74 */ 75 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx, 76 struct ubi_vtbl_record *vtbl_rec) 77 { 78 int i, err; 79 uint32_t crc; 80 struct ubi_volume *layout_vol; 81 82 ubi_assert(idx >= 0 && idx < ubi->vtbl_slots); 83 layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)]; 84 85 if (!vtbl_rec) 86 vtbl_rec = &empty_vtbl_record; 87 else { 88 crc = crc32(UBI_CRC32_INIT, vtbl_rec, UBI_VTBL_RECORD_SIZE_CRC); 89 vtbl_rec->crc = cpu_to_be32(crc); 90 } 91 92 memcpy(&ubi->vtbl[idx], vtbl_rec, sizeof(struct ubi_vtbl_record)); 93 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { 94 err = ubi_eba_unmap_leb(ubi, layout_vol, i); 95 if (err) 96 return err; 97 98 err = ubi_eba_write_leb(ubi, layout_vol, i, ubi->vtbl, 0, 99 ubi->vtbl_size); 100 if (err) 101 return err; 102 } 103 104 self_vtbl_check(ubi); 105 return 0; 106 } 107 108 /** 109 * ubi_vtbl_rename_volumes - rename UBI volumes in the volume table. 110 * @ubi: UBI device description object 111 * @rename_list: list of &struct ubi_rename_entry objects 112 * 113 * This function re-names multiple volumes specified in @req in the volume 114 * table. Returns zero in case of success and a negative error code in case of 115 * failure. 116 */ 117 int ubi_vtbl_rename_volumes(struct ubi_device *ubi, 118 struct list_head *rename_list) 119 { 120 int i, err; 121 struct ubi_rename_entry *re; 122 struct ubi_volume *layout_vol; 123 124 list_for_each_entry(re, rename_list, list) { 125 uint32_t crc; 126 struct ubi_volume *vol = re->desc->vol; 127 struct ubi_vtbl_record *vtbl_rec = &ubi->vtbl[vol->vol_id]; 128 129 if (re->remove) { 130 memcpy(vtbl_rec, &empty_vtbl_record, 131 sizeof(struct ubi_vtbl_record)); 132 continue; 133 } 134 135 vtbl_rec->name_len = cpu_to_be16(re->new_name_len); 136 memcpy(vtbl_rec->name, re->new_name, re->new_name_len); 137 memset(vtbl_rec->name + re->new_name_len, 0, 138 UBI_VOL_NAME_MAX + 1 - re->new_name_len); 139 crc = crc32(UBI_CRC32_INIT, vtbl_rec, 140 UBI_VTBL_RECORD_SIZE_CRC); 141 vtbl_rec->crc = cpu_to_be32(crc); 142 } 143 144 layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)]; 145 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { 146 err = ubi_eba_unmap_leb(ubi, layout_vol, i); 147 if (err) 148 return err; 149 150 err = ubi_eba_write_leb(ubi, layout_vol, i, ubi->vtbl, 0, 151 ubi->vtbl_size); 152 if (err) 153 return err; 154 } 155 156 return 0; 157 } 158 159 /** 160 * vtbl_check - check if volume table is not corrupted and sensible. 161 * @ubi: UBI device description object 162 * @vtbl: volume table 163 * 164 * This function returns zero if @vtbl is all right, %1 if CRC is incorrect, 165 * and %-EINVAL if it contains inconsistent data. 166 */ 167 static int vtbl_check(const struct ubi_device *ubi, 168 const struct ubi_vtbl_record *vtbl) 169 { 170 int i, n, reserved_pebs, alignment, data_pad, vol_type, name_len; 171 int upd_marker, err; 172 uint32_t crc; 173 const char *name; 174 175 for (i = 0; i < ubi->vtbl_slots; i++) { 176 cond_resched(); 177 178 reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs); 179 alignment = be32_to_cpu(vtbl[i].alignment); 180 data_pad = be32_to_cpu(vtbl[i].data_pad); 181 upd_marker = vtbl[i].upd_marker; 182 vol_type = vtbl[i].vol_type; 183 name_len = be16_to_cpu(vtbl[i].name_len); 184 name = &vtbl[i].name[0]; 185 186 crc = crc32(UBI_CRC32_INIT, &vtbl[i], UBI_VTBL_RECORD_SIZE_CRC); 187 if (be32_to_cpu(vtbl[i].crc) != crc) { 188 ubi_err("bad CRC at record %u: %#08x, not %#08x", 189 i, crc, be32_to_cpu(vtbl[i].crc)); 190 ubi_dump_vtbl_record(&vtbl[i], i); 191 return 1; 192 } 193 194 if (reserved_pebs == 0) { 195 if (memcmp(&vtbl[i], &empty_vtbl_record, 196 UBI_VTBL_RECORD_SIZE)) { 197 err = 2; 198 goto bad; 199 } 200 continue; 201 } 202 203 if (reserved_pebs < 0 || alignment < 0 || data_pad < 0 || 204 name_len < 0) { 205 err = 3; 206 goto bad; 207 } 208 209 if (alignment > ubi->leb_size || alignment == 0) { 210 err = 4; 211 goto bad; 212 } 213 214 n = alignment & (ubi->min_io_size - 1); 215 if (alignment != 1 && n) { 216 err = 5; 217 goto bad; 218 } 219 220 n = ubi->leb_size % alignment; 221 if (data_pad != n) { 222 ubi_err("bad data_pad, has to be %d", n); 223 err = 6; 224 goto bad; 225 } 226 227 if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) { 228 err = 7; 229 goto bad; 230 } 231 232 if (upd_marker != 0 && upd_marker != 1) { 233 err = 8; 234 goto bad; 235 } 236 237 if (reserved_pebs > ubi->good_peb_count) { 238 ubi_err("too large reserved_pebs %d, good PEBs %d", 239 reserved_pebs, ubi->good_peb_count); 240 err = 9; 241 goto bad; 242 } 243 244 if (name_len > UBI_VOL_NAME_MAX) { 245 err = 10; 246 goto bad; 247 } 248 249 if (name[0] == '\0') { 250 err = 11; 251 goto bad; 252 } 253 254 if (name_len != strnlen(name, name_len + 1)) { 255 err = 12; 256 goto bad; 257 } 258 } 259 260 /* Checks that all names are unique */ 261 for (i = 0; i < ubi->vtbl_slots - 1; i++) { 262 for (n = i + 1; n < ubi->vtbl_slots; n++) { 263 int len1 = be16_to_cpu(vtbl[i].name_len); 264 int len2 = be16_to_cpu(vtbl[n].name_len); 265 266 if (len1 > 0 && len1 == len2 && 267 #ifndef __UBOOT__ 268 !strncmp(vtbl[i].name, vtbl[n].name, len1)) { 269 #else 270 !strncmp((char *)vtbl[i].name, vtbl[n].name, len1)) { 271 #endif 272 ubi_err("volumes %d and %d have the same name \"%s\"", 273 i, n, vtbl[i].name); 274 ubi_dump_vtbl_record(&vtbl[i], i); 275 ubi_dump_vtbl_record(&vtbl[n], n); 276 return -EINVAL; 277 } 278 } 279 } 280 281 return 0; 282 283 bad: 284 ubi_err("volume table check failed: record %d, error %d", i, err); 285 ubi_dump_vtbl_record(&vtbl[i], i); 286 return -EINVAL; 287 } 288 289 /** 290 * create_vtbl - create a copy of volume table. 291 * @ubi: UBI device description object 292 * @ai: attaching information 293 * @copy: number of the volume table copy 294 * @vtbl: contents of the volume table 295 * 296 * This function returns zero in case of success and a negative error code in 297 * case of failure. 298 */ 299 static int create_vtbl(struct ubi_device *ubi, struct ubi_attach_info *ai, 300 int copy, void *vtbl) 301 { 302 int err, tries = 0; 303 struct ubi_vid_hdr *vid_hdr; 304 struct ubi_ainf_peb *new_aeb; 305 306 dbg_gen("create volume table (copy #%d)", copy + 1); 307 308 vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL); 309 if (!vid_hdr) 310 return -ENOMEM; 311 312 retry: 313 new_aeb = ubi_early_get_peb(ubi, ai); 314 if (IS_ERR(new_aeb)) { 315 err = PTR_ERR(new_aeb); 316 goto out_free; 317 } 318 319 vid_hdr->vol_type = UBI_LAYOUT_VOLUME_TYPE; 320 vid_hdr->vol_id = cpu_to_be32(UBI_LAYOUT_VOLUME_ID); 321 vid_hdr->compat = UBI_LAYOUT_VOLUME_COMPAT; 322 vid_hdr->data_size = vid_hdr->used_ebs = 323 vid_hdr->data_pad = cpu_to_be32(0); 324 vid_hdr->lnum = cpu_to_be32(copy); 325 vid_hdr->sqnum = cpu_to_be64(++ai->max_sqnum); 326 327 /* The EC header is already there, write the VID header */ 328 err = ubi_io_write_vid_hdr(ubi, new_aeb->pnum, vid_hdr); 329 if (err) 330 goto write_error; 331 332 /* Write the layout volume contents */ 333 err = ubi_io_write_data(ubi, vtbl, new_aeb->pnum, 0, ubi->vtbl_size); 334 if (err) 335 goto write_error; 336 337 /* 338 * And add it to the attaching information. Don't delete the old version 339 * of this LEB as it will be deleted and freed in 'ubi_add_to_av()'. 340 */ 341 err = ubi_add_to_av(ubi, ai, new_aeb->pnum, new_aeb->ec, vid_hdr, 0); 342 kmem_cache_free(ai->aeb_slab_cache, new_aeb); 343 ubi_free_vid_hdr(ubi, vid_hdr); 344 return err; 345 346 write_error: 347 if (err == -EIO && ++tries <= 5) { 348 /* 349 * Probably this physical eraseblock went bad, try to pick 350 * another one. 351 */ 352 list_add(&new_aeb->u.list, &ai->erase); 353 goto retry; 354 } 355 kmem_cache_free(ai->aeb_slab_cache, new_aeb); 356 out_free: 357 ubi_free_vid_hdr(ubi, vid_hdr); 358 return err; 359 360 } 361 362 /** 363 * process_lvol - process the layout volume. 364 * @ubi: UBI device description object 365 * @ai: attaching information 366 * @av: layout volume attaching information 367 * 368 * This function is responsible for reading the layout volume, ensuring it is 369 * not corrupted, and recovering from corruptions if needed. Returns volume 370 * table in case of success and a negative error code in case of failure. 371 */ 372 static struct ubi_vtbl_record *process_lvol(struct ubi_device *ubi, 373 struct ubi_attach_info *ai, 374 struct ubi_ainf_volume *av) 375 { 376 int err; 377 struct rb_node *rb; 378 struct ubi_ainf_peb *aeb; 379 struct ubi_vtbl_record *leb[UBI_LAYOUT_VOLUME_EBS] = { NULL, NULL }; 380 int leb_corrupted[UBI_LAYOUT_VOLUME_EBS] = {1, 1}; 381 382 /* 383 * UBI goes through the following steps when it changes the layout 384 * volume: 385 * a. erase LEB 0; 386 * b. write new data to LEB 0; 387 * c. erase LEB 1; 388 * d. write new data to LEB 1. 389 * 390 * Before the change, both LEBs contain the same data. 391 * 392 * Due to unclean reboots, the contents of LEB 0 may be lost, but there 393 * should LEB 1. So it is OK if LEB 0 is corrupted while LEB 1 is not. 394 * Similarly, LEB 1 may be lost, but there should be LEB 0. And 395 * finally, unclean reboots may result in a situation when neither LEB 396 * 0 nor LEB 1 are corrupted, but they are different. In this case, LEB 397 * 0 contains more recent information. 398 * 399 * So the plan is to first check LEB 0. Then 400 * a. if LEB 0 is OK, it must be containing the most recent data; then 401 * we compare it with LEB 1, and if they are different, we copy LEB 402 * 0 to LEB 1; 403 * b. if LEB 0 is corrupted, but LEB 1 has to be OK, and we copy LEB 1 404 * to LEB 0. 405 */ 406 407 dbg_gen("check layout volume"); 408 409 /* Read both LEB 0 and LEB 1 into memory */ 410 ubi_rb_for_each_entry(rb, aeb, &av->root, u.rb) { 411 leb[aeb->lnum] = vzalloc(ubi->vtbl_size); 412 if (!leb[aeb->lnum]) { 413 err = -ENOMEM; 414 goto out_free; 415 } 416 417 err = ubi_io_read_data(ubi, leb[aeb->lnum], aeb->pnum, 0, 418 ubi->vtbl_size); 419 if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) 420 /* 421 * Scrub the PEB later. Note, -EBADMSG indicates an 422 * uncorrectable ECC error, but we have our own CRC and 423 * the data will be checked later. If the data is OK, 424 * the PEB will be scrubbed (because we set 425 * aeb->scrub). If the data is not OK, the contents of 426 * the PEB will be recovered from the second copy, and 427 * aeb->scrub will be cleared in 428 * 'ubi_add_to_av()'. 429 */ 430 aeb->scrub = 1; 431 else if (err) 432 goto out_free; 433 } 434 435 err = -EINVAL; 436 if (leb[0]) { 437 leb_corrupted[0] = vtbl_check(ubi, leb[0]); 438 if (leb_corrupted[0] < 0) 439 goto out_free; 440 } 441 442 if (!leb_corrupted[0]) { 443 /* LEB 0 is OK */ 444 if (leb[1]) 445 leb_corrupted[1] = memcmp(leb[0], leb[1], 446 ubi->vtbl_size); 447 if (leb_corrupted[1]) { 448 ubi_warn("volume table copy #2 is corrupted"); 449 err = create_vtbl(ubi, ai, 1, leb[0]); 450 if (err) 451 goto out_free; 452 ubi_msg("volume table was restored"); 453 } 454 455 /* Both LEB 1 and LEB 2 are OK and consistent */ 456 vfree(leb[1]); 457 return leb[0]; 458 } else { 459 /* LEB 0 is corrupted or does not exist */ 460 if (leb[1]) { 461 leb_corrupted[1] = vtbl_check(ubi, leb[1]); 462 if (leb_corrupted[1] < 0) 463 goto out_free; 464 } 465 if (leb_corrupted[1]) { 466 /* Both LEB 0 and LEB 1 are corrupted */ 467 ubi_err("both volume tables are corrupted"); 468 goto out_free; 469 } 470 471 ubi_warn("volume table copy #1 is corrupted"); 472 err = create_vtbl(ubi, ai, 0, leb[1]); 473 if (err) 474 goto out_free; 475 ubi_msg("volume table was restored"); 476 477 vfree(leb[0]); 478 return leb[1]; 479 } 480 481 out_free: 482 vfree(leb[0]); 483 vfree(leb[1]); 484 return ERR_PTR(err); 485 } 486 487 /** 488 * create_empty_lvol - create empty layout volume. 489 * @ubi: UBI device description object 490 * @ai: attaching information 491 * 492 * This function returns volume table contents in case of success and a 493 * negative error code in case of failure. 494 */ 495 static struct ubi_vtbl_record *create_empty_lvol(struct ubi_device *ubi, 496 struct ubi_attach_info *ai) 497 { 498 int i; 499 struct ubi_vtbl_record *vtbl; 500 501 vtbl = vzalloc(ubi->vtbl_size); 502 if (!vtbl) 503 return ERR_PTR(-ENOMEM); 504 505 for (i = 0; i < ubi->vtbl_slots; i++) 506 memcpy(&vtbl[i], &empty_vtbl_record, UBI_VTBL_RECORD_SIZE); 507 508 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { 509 int err; 510 511 err = create_vtbl(ubi, ai, i, vtbl); 512 if (err) { 513 vfree(vtbl); 514 return ERR_PTR(err); 515 } 516 } 517 518 return vtbl; 519 } 520 521 /** 522 * init_volumes - initialize volume information for existing volumes. 523 * @ubi: UBI device description object 524 * @ai: scanning information 525 * @vtbl: volume table 526 * 527 * This function allocates volume description objects for existing volumes. 528 * Returns zero in case of success and a negative error code in case of 529 * failure. 530 */ 531 static int init_volumes(struct ubi_device *ubi, 532 const struct ubi_attach_info *ai, 533 const struct ubi_vtbl_record *vtbl) 534 { 535 int i, reserved_pebs = 0; 536 struct ubi_ainf_volume *av; 537 struct ubi_volume *vol; 538 539 for (i = 0; i < ubi->vtbl_slots; i++) { 540 cond_resched(); 541 542 if (be32_to_cpu(vtbl[i].reserved_pebs) == 0) 543 continue; /* Empty record */ 544 545 vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); 546 if (!vol) 547 return -ENOMEM; 548 549 vol->reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs); 550 vol->alignment = be32_to_cpu(vtbl[i].alignment); 551 vol->data_pad = be32_to_cpu(vtbl[i].data_pad); 552 vol->upd_marker = vtbl[i].upd_marker; 553 vol->vol_type = vtbl[i].vol_type == UBI_VID_DYNAMIC ? 554 UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME; 555 vol->name_len = be16_to_cpu(vtbl[i].name_len); 556 vol->usable_leb_size = ubi->leb_size - vol->data_pad; 557 memcpy(vol->name, vtbl[i].name, vol->name_len); 558 vol->name[vol->name_len] = '\0'; 559 vol->vol_id = i; 560 561 if (vtbl[i].flags & UBI_VTBL_AUTORESIZE_FLG) { 562 /* Auto re-size flag may be set only for one volume */ 563 if (ubi->autoresize_vol_id != -1) { 564 ubi_err("more than one auto-resize volume (%d and %d)", 565 ubi->autoresize_vol_id, i); 566 kfree(vol); 567 return -EINVAL; 568 } 569 570 ubi->autoresize_vol_id = i; 571 } 572 573 ubi_assert(!ubi->volumes[i]); 574 ubi->volumes[i] = vol; 575 ubi->vol_count += 1; 576 vol->ubi = ubi; 577 reserved_pebs += vol->reserved_pebs; 578 579 /* 580 * In case of dynamic volume UBI knows nothing about how many 581 * data is stored there. So assume the whole volume is used. 582 */ 583 if (vol->vol_type == UBI_DYNAMIC_VOLUME) { 584 vol->used_ebs = vol->reserved_pebs; 585 vol->last_eb_bytes = vol->usable_leb_size; 586 vol->used_bytes = 587 (long long)vol->used_ebs * vol->usable_leb_size; 588 continue; 589 } 590 591 /* Static volumes only */ 592 av = ubi_find_av(ai, i); 593 if (!av) { 594 /* 595 * No eraseblocks belonging to this volume found. We 596 * don't actually know whether this static volume is 597 * completely corrupted or just contains no data. And 598 * we cannot know this as long as data size is not 599 * stored on flash. So we just assume the volume is 600 * empty. FIXME: this should be handled. 601 */ 602 continue; 603 } 604 605 if (av->leb_count != av->used_ebs) { 606 /* 607 * We found a static volume which misses several 608 * eraseblocks. Treat it as corrupted. 609 */ 610 ubi_warn("static volume %d misses %d LEBs - corrupted", 611 av->vol_id, av->used_ebs - av->leb_count); 612 vol->corrupted = 1; 613 continue; 614 } 615 616 vol->used_ebs = av->used_ebs; 617 vol->used_bytes = 618 (long long)(vol->used_ebs - 1) * vol->usable_leb_size; 619 vol->used_bytes += av->last_data_size; 620 vol->last_eb_bytes = av->last_data_size; 621 } 622 623 /* And add the layout volume */ 624 vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); 625 if (!vol) 626 return -ENOMEM; 627 628 vol->reserved_pebs = UBI_LAYOUT_VOLUME_EBS; 629 vol->alignment = UBI_LAYOUT_VOLUME_ALIGN; 630 vol->vol_type = UBI_DYNAMIC_VOLUME; 631 vol->name_len = sizeof(UBI_LAYOUT_VOLUME_NAME) - 1; 632 memcpy(vol->name, UBI_LAYOUT_VOLUME_NAME, vol->name_len + 1); 633 vol->usable_leb_size = ubi->leb_size; 634 vol->used_ebs = vol->reserved_pebs; 635 vol->last_eb_bytes = vol->reserved_pebs; 636 vol->used_bytes = 637 (long long)vol->used_ebs * (ubi->leb_size - vol->data_pad); 638 vol->vol_id = UBI_LAYOUT_VOLUME_ID; 639 vol->ref_count = 1; 640 641 ubi_assert(!ubi->volumes[i]); 642 ubi->volumes[vol_id2idx(ubi, vol->vol_id)] = vol; 643 reserved_pebs += vol->reserved_pebs; 644 ubi->vol_count += 1; 645 vol->ubi = ubi; 646 647 if (reserved_pebs > ubi->avail_pebs) { 648 ubi_err("not enough PEBs, required %d, available %d", 649 reserved_pebs, ubi->avail_pebs); 650 if (ubi->corr_peb_count) 651 ubi_err("%d PEBs are corrupted and not used", 652 ubi->corr_peb_count); 653 } 654 ubi->rsvd_pebs += reserved_pebs; 655 ubi->avail_pebs -= reserved_pebs; 656 657 return 0; 658 } 659 660 /** 661 * check_av - check volume attaching information. 662 * @vol: UBI volume description object 663 * @av: volume attaching information 664 * 665 * This function returns zero if the volume attaching information is consistent 666 * to the data read from the volume tabla, and %-EINVAL if not. 667 */ 668 static int check_av(const struct ubi_volume *vol, 669 const struct ubi_ainf_volume *av) 670 { 671 int err; 672 673 if (av->highest_lnum >= vol->reserved_pebs) { 674 err = 1; 675 goto bad; 676 } 677 if (av->leb_count > vol->reserved_pebs) { 678 err = 2; 679 goto bad; 680 } 681 if (av->vol_type != vol->vol_type) { 682 err = 3; 683 goto bad; 684 } 685 if (av->used_ebs > vol->reserved_pebs) { 686 err = 4; 687 goto bad; 688 } 689 if (av->data_pad != vol->data_pad) { 690 err = 5; 691 goto bad; 692 } 693 return 0; 694 695 bad: 696 ubi_err("bad attaching information, error %d", err); 697 ubi_dump_av(av); 698 ubi_dump_vol_info(vol); 699 return -EINVAL; 700 } 701 702 /** 703 * check_attaching_info - check that attaching information. 704 * @ubi: UBI device description object 705 * @ai: attaching information 706 * 707 * Even though we protect on-flash data by CRC checksums, we still don't trust 708 * the media. This function ensures that attaching information is consistent to 709 * the information read from the volume table. Returns zero if the attaching 710 * information is OK and %-EINVAL if it is not. 711 */ 712 static int check_attaching_info(const struct ubi_device *ubi, 713 struct ubi_attach_info *ai) 714 { 715 int err, i; 716 struct ubi_ainf_volume *av; 717 struct ubi_volume *vol; 718 719 if (ai->vols_found > UBI_INT_VOL_COUNT + ubi->vtbl_slots) { 720 ubi_err("found %d volumes while attaching, maximum is %d + %d", 721 ai->vols_found, UBI_INT_VOL_COUNT, ubi->vtbl_slots); 722 return -EINVAL; 723 } 724 725 if (ai->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT && 726 ai->highest_vol_id < UBI_INTERNAL_VOL_START) { 727 ubi_err("too large volume ID %d found", ai->highest_vol_id); 728 return -EINVAL; 729 } 730 731 for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) { 732 cond_resched(); 733 734 av = ubi_find_av(ai, i); 735 vol = ubi->volumes[i]; 736 if (!vol) { 737 if (av) 738 ubi_remove_av(ai, av); 739 continue; 740 } 741 742 if (vol->reserved_pebs == 0) { 743 ubi_assert(i < ubi->vtbl_slots); 744 745 if (!av) 746 continue; 747 748 /* 749 * During attaching we found a volume which does not 750 * exist according to the information in the volume 751 * table. This must have happened due to an unclean 752 * reboot while the volume was being removed. Discard 753 * these eraseblocks. 754 */ 755 ubi_msg("finish volume %d removal", av->vol_id); 756 ubi_remove_av(ai, av); 757 } else if (av) { 758 err = check_av(vol, av); 759 if (err) 760 return err; 761 } 762 } 763 764 return 0; 765 } 766 767 /** 768 * ubi_read_volume_table - read the volume table. 769 * @ubi: UBI device description object 770 * @ai: attaching information 771 * 772 * This function reads volume table, checks it, recover from errors if needed, 773 * or creates it if needed. Returns zero in case of success and a negative 774 * error code in case of failure. 775 */ 776 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai) 777 { 778 int i, err; 779 struct ubi_ainf_volume *av; 780 781 empty_vtbl_record.crc = cpu_to_be32(0xf116c36b); 782 783 /* 784 * The number of supported volumes is limited by the eraseblock size 785 * and by the UBI_MAX_VOLUMES constant. 786 */ 787 ubi->vtbl_slots = ubi->leb_size / UBI_VTBL_RECORD_SIZE; 788 if (ubi->vtbl_slots > UBI_MAX_VOLUMES) 789 ubi->vtbl_slots = UBI_MAX_VOLUMES; 790 791 ubi->vtbl_size = ubi->vtbl_slots * UBI_VTBL_RECORD_SIZE; 792 ubi->vtbl_size = ALIGN(ubi->vtbl_size, ubi->min_io_size); 793 794 av = ubi_find_av(ai, UBI_LAYOUT_VOLUME_ID); 795 if (!av) { 796 /* 797 * No logical eraseblocks belonging to the layout volume were 798 * found. This could mean that the flash is just empty. In 799 * this case we create empty layout volume. 800 * 801 * But if flash is not empty this must be a corruption or the 802 * MTD device just contains garbage. 803 */ 804 if (ai->is_empty) { 805 ubi->vtbl = create_empty_lvol(ubi, ai); 806 if (IS_ERR(ubi->vtbl)) 807 return PTR_ERR(ubi->vtbl); 808 } else { 809 ubi_err("the layout volume was not found"); 810 return -EINVAL; 811 } 812 } else { 813 if (av->leb_count > UBI_LAYOUT_VOLUME_EBS) { 814 /* This must not happen with proper UBI images */ 815 ubi_err("too many LEBs (%d) in layout volume", 816 av->leb_count); 817 return -EINVAL; 818 } 819 820 ubi->vtbl = process_lvol(ubi, ai, av); 821 if (IS_ERR(ubi->vtbl)) 822 return PTR_ERR(ubi->vtbl); 823 } 824 825 ubi->avail_pebs = ubi->good_peb_count - ubi->corr_peb_count; 826 827 /* 828 * The layout volume is OK, initialize the corresponding in-RAM data 829 * structures. 830 */ 831 err = init_volumes(ubi, ai, ubi->vtbl); 832 if (err) 833 goto out_free; 834 835 /* 836 * Make sure that the attaching information is consistent to the 837 * information stored in the volume table. 838 */ 839 err = check_attaching_info(ubi, ai); 840 if (err) 841 goto out_free; 842 843 return 0; 844 845 out_free: 846 vfree(ubi->vtbl); 847 for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) { 848 kfree(ubi->volumes[i]); 849 ubi->volumes[i] = NULL; 850 } 851 return err; 852 } 853 854 /** 855 * self_vtbl_check - check volume table. 856 * @ubi: UBI device description object 857 */ 858 static void self_vtbl_check(const struct ubi_device *ubi) 859 { 860 if (!ubi_dbg_chk_gen(ubi)) 861 return; 862 863 if (vtbl_check(ubi, ubi->vtbl)) { 864 ubi_err("self-check failed"); 865 BUG(); 866 } 867 } 868