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