1// SPDX-License-Identifier: GPL-2.0-or-later 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#include <linux/crc32.h> 49#include <linux/err.h> 50#include <linux/slab.h> 51#include <asm/div64.h> 52#include "ubi.h" 53 54static void self_vtbl_check(const struct ubi_device *ubi); 55 56/* Empty volume table record */ 57static struct ubi_vtbl_record empty_vtbl_record; 58 59/** 60 * ubi_update_layout_vol - helper for updatting layout volumes on flash 61 * @ubi: UBI device description object 62 */ 63static int ubi_update_layout_vol(struct ubi_device *ubi) 64{ 65 struct ubi_volume *layout_vol; 66 int i, err; 67 68 layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)]; 69 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { 70 err = ubi_eba_atomic_leb_change(ubi, layout_vol, i, ubi->vtbl, 71 ubi->vtbl_size); 72 if (err) 73 return err; 74 } 75 76 return 0; 77} 78 79/** 80 * ubi_change_vtbl_record - change volume table record. 81 * @ubi: UBI device description object 82 * @idx: table index to change 83 * @vtbl_rec: new volume table record 84 * 85 * This function changes volume table record @idx. If @vtbl_rec is %NULL, empty 86 * volume table record is written. The caller does not have to calculate CRC of 87 * the record as it is done by this function. Returns zero in case of success 88 * and a negative error code in case of failure. 89 */ 90int ubi_change_vtbl_record(struct ubi_device *ubi, int idx, 91 struct ubi_vtbl_record *vtbl_rec) 92{ 93 int err; 94 uint32_t crc; 95 96 ubi_assert(idx >= 0 && idx < ubi->vtbl_slots); 97 98 if (!vtbl_rec) 99 vtbl_rec = &empty_vtbl_record; 100 else { 101 crc = crc32(UBI_CRC32_INIT, vtbl_rec, UBI_VTBL_RECORD_SIZE_CRC); 102 vtbl_rec->crc = cpu_to_be32(crc); 103 } 104 105 memcpy(&ubi->vtbl[idx], vtbl_rec, sizeof(struct ubi_vtbl_record)); 106 err = ubi_update_layout_vol(ubi); 107 108 self_vtbl_check(ubi); 109 return err ? err : 0; 110} 111 112/** 113 * ubi_vtbl_rename_volumes - rename UBI volumes in the volume table. 114 * @ubi: UBI device description object 115 * @rename_list: list of &struct ubi_rename_entry objects 116 * 117 * This function re-names multiple volumes specified in @req in the volume 118 * table. Returns zero in case of success and a negative error code in case of 119 * failure. 120 */ 121int ubi_vtbl_rename_volumes(struct ubi_device *ubi, 122 struct list_head *rename_list) 123{ 124 struct ubi_rename_entry *re; 125 126 list_for_each_entry(re, rename_list, list) { 127 uint32_t crc; 128 struct ubi_volume *vol = re->desc->vol; 129 struct ubi_vtbl_record *vtbl_rec = &ubi->vtbl[vol->vol_id]; 130 131 if (re->remove) { 132 memcpy(vtbl_rec, &empty_vtbl_record, 133 sizeof(struct ubi_vtbl_record)); 134 continue; 135 } 136 137 vtbl_rec->name_len = cpu_to_be16(re->new_name_len); 138 memcpy(vtbl_rec->name, re->new_name, re->new_name_len); 139 memset(vtbl_rec->name + re->new_name_len, 0, 140 UBI_VOL_NAME_MAX + 1 - re->new_name_len); 141 crc = crc32(UBI_CRC32_INIT, vtbl_rec, 142 UBI_VTBL_RECORD_SIZE_CRC); 143 vtbl_rec->crc = cpu_to_be32(crc); 144 } 145 146 return ubi_update_layout_vol(ubi); 147} 148 149/** 150 * vtbl_check - check if volume table is not corrupted and sensible. 151 * @ubi: UBI device description object 152 * @vtbl: volume table 153 * 154 * This function returns zero if @vtbl is all right, %1 if CRC is incorrect, 155 * and %-EINVAL if it contains inconsistent data. 156 */ 157static int vtbl_check(const struct ubi_device *ubi, 158 const struct ubi_vtbl_record *vtbl) 159{ 160 int i, n, reserved_pebs, alignment, data_pad, vol_type, name_len; 161 int upd_marker, err; 162 uint32_t crc; 163 const char *name; 164 165 for (i = 0; i < ubi->vtbl_slots; i++) { 166 cond_resched(); 167 168 reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs); 169 alignment = be32_to_cpu(vtbl[i].alignment); 170 data_pad = be32_to_cpu(vtbl[i].data_pad); 171 upd_marker = vtbl[i].upd_marker; 172 vol_type = vtbl[i].vol_type; 173 name_len = be16_to_cpu(vtbl[i].name_len); 174 name = &vtbl[i].name[0]; 175 176 crc = crc32(UBI_CRC32_INIT, &vtbl[i], UBI_VTBL_RECORD_SIZE_CRC); 177 if (be32_to_cpu(vtbl[i].crc) != crc) { 178 ubi_err(ubi, "bad CRC at record %u: %#08x, not %#08x", 179 i, crc, be32_to_cpu(vtbl[i].crc)); 180 ubi_dump_vtbl_record(&vtbl[i], i); 181 return 1; 182 } 183 184 if (reserved_pebs == 0) { 185 if (memcmp(&vtbl[i], &empty_vtbl_record, 186 UBI_VTBL_RECORD_SIZE)) { 187 err = 2; 188 goto bad; 189 } 190 continue; 191 } 192 193 if (reserved_pebs < 0 || alignment < 0 || data_pad < 0 || 194 name_len < 0) { 195 err = 3; 196 goto bad; 197 } 198 199 if (alignment > ubi->leb_size || alignment == 0) { 200 err = 4; 201 goto bad; 202 } 203 204 n = alignment & (ubi->min_io_size - 1); 205 if (alignment != 1 && n) { 206 err = 5; 207 goto bad; 208 } 209 210 n = ubi->leb_size % alignment; 211 if (data_pad != n) { 212 ubi_err(ubi, "bad data_pad, has to be %d", n); 213 err = 6; 214 goto bad; 215 } 216 217 if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) { 218 err = 7; 219 goto bad; 220 } 221 222 if (upd_marker != 0 && upd_marker != 1) { 223 err = 8; 224 goto bad; 225 } 226 227 if (reserved_pebs > ubi->good_peb_count) { 228 ubi_err(ubi, "too large reserved_pebs %d, good PEBs %d", 229 reserved_pebs, ubi->good_peb_count); 230 err = 9; 231 goto bad; 232 } 233 234 if (name_len > UBI_VOL_NAME_MAX) { 235 err = 10; 236 goto bad; 237 } 238 239 if (name[0] == '\0') { 240 err = 11; 241 goto bad; 242 } 243 244 if (name_len != strnlen(name, name_len + 1)) { 245 err = 12; 246 goto bad; 247 } 248 } 249 250 /* Checks that all names are unique */ 251 for (i = 0; i < ubi->vtbl_slots - 1; i++) { 252 for (n = i + 1; n < ubi->vtbl_slots; n++) { 253 int len1 = be16_to_cpu(vtbl[i].name_len); 254 int len2 = be16_to_cpu(vtbl[n].name_len); 255 256 if (len1 > 0 && len1 == len2 && 257 !strncmp(vtbl[i].name, vtbl[n].name, len1)) { 258 ubi_err(ubi, "volumes %d and %d have the same name \"%s\"", 259 i, n, vtbl[i].name); 260 ubi_dump_vtbl_record(&vtbl[i], i); 261 ubi_dump_vtbl_record(&vtbl[n], n); 262 return -EINVAL; 263 } 264 } 265 } 266 267 return 0; 268 269bad: 270 ubi_err(ubi, "volume table check failed: record %d, error %d", i, err); 271 ubi_dump_vtbl_record(&vtbl[i], i); 272 return -EINVAL; 273} 274 275/** 276 * create_vtbl - create a copy of volume table. 277 * @ubi: UBI device description object 278 * @ai: attaching information 279 * @copy: number of the volume table copy 280 * @vtbl: contents of the volume table 281 * 282 * This function returns zero in case of success and a negative error code in 283 * case of failure. 284 */ 285static int create_vtbl(struct ubi_device *ubi, struct ubi_attach_info *ai, 286 int copy, void *vtbl) 287{ 288 int err, tries = 0; 289 struct ubi_vid_io_buf *vidb; 290 struct ubi_vid_hdr *vid_hdr; 291 struct ubi_ainf_peb *new_aeb; 292 293 dbg_gen("create volume table (copy #%d)", copy + 1); 294 295 vidb = ubi_alloc_vid_buf(ubi, GFP_KERNEL); 296 if (!vidb) 297 return -ENOMEM; 298 299 vid_hdr = ubi_get_vid_hdr(vidb); 300 301retry: 302 new_aeb = ubi_early_get_peb(ubi, ai); 303 if (IS_ERR(new_aeb)) { 304 err = PTR_ERR(new_aeb); 305 goto out_free; 306 } 307 308 vid_hdr->vol_type = UBI_LAYOUT_VOLUME_TYPE; 309 vid_hdr->vol_id = cpu_to_be32(UBI_LAYOUT_VOLUME_ID); 310 vid_hdr->compat = UBI_LAYOUT_VOLUME_COMPAT; 311 vid_hdr->data_size = vid_hdr->used_ebs = 312 vid_hdr->data_pad = cpu_to_be32(0); 313 vid_hdr->lnum = cpu_to_be32(copy); 314 vid_hdr->sqnum = cpu_to_be64(++ai->max_sqnum); 315 316 /* The EC header is already there, write the VID header */ 317 err = ubi_io_write_vid_hdr(ubi, new_aeb->pnum, vidb); 318 if (err) 319 goto write_error; 320 321 /* Write the layout volume contents */ 322 err = ubi_io_write_data(ubi, vtbl, new_aeb->pnum, 0, ubi->vtbl_size); 323 if (err) 324 goto write_error; 325 326 /* 327 * And add it to the attaching information. Don't delete the old version 328 * of this LEB as it will be deleted and freed in 'ubi_add_to_av()'. 329 */ 330 err = ubi_add_to_av(ubi, ai, new_aeb->pnum, new_aeb->ec, vid_hdr, 0); 331 ubi_free_aeb(ai, new_aeb); 332 ubi_free_vid_buf(vidb); 333 return err; 334 335write_error: 336 if (err == -EIO && ++tries <= 5) { 337 /* 338 * Probably this physical eraseblock went bad, try to pick 339 * another one. 340 */ 341 list_add(&new_aeb->u.list, &ai->erase); 342 goto retry; 343 } 344 ubi_free_aeb(ai, new_aeb); 345out_free: 346 ubi_free_vid_buf(vidb); 347 return err; 348 349} 350 351/** 352 * process_lvol - process the layout volume. 353 * @ubi: UBI device description object 354 * @ai: attaching information 355 * @av: layout volume attaching information 356 * 357 * This function is responsible for reading the layout volume, ensuring it is 358 * not corrupted, and recovering from corruptions if needed. Returns volume 359 * table in case of success and a negative error code in case of failure. 360 */ 361static struct ubi_vtbl_record *process_lvol(struct ubi_device *ubi, 362 struct ubi_attach_info *ai, 363 struct ubi_ainf_volume *av) 364{ 365 int err; 366 struct rb_node *rb; 367 struct ubi_ainf_peb *aeb; 368 struct ubi_vtbl_record *leb[UBI_LAYOUT_VOLUME_EBS] = { NULL, NULL }; 369 int leb_corrupted[UBI_LAYOUT_VOLUME_EBS] = {1, 1}; 370 371 /* 372 * UBI goes through the following steps when it changes the layout 373 * volume: 374 * a. erase LEB 0; 375 * b. write new data to LEB 0; 376 * c. erase LEB 1; 377 * d. write new data to LEB 1. 378 * 379 * Before the change, both LEBs contain the same data. 380 * 381 * Due to unclean reboots, the contents of LEB 0 may be lost, but there 382 * should LEB 1. So it is OK if LEB 0 is corrupted while LEB 1 is not. 383 * Similarly, LEB 1 may be lost, but there should be LEB 0. And 384 * finally, unclean reboots may result in a situation when neither LEB 385 * 0 nor LEB 1 are corrupted, but they are different. In this case, LEB 386 * 0 contains more recent information. 387 * 388 * So the plan is to first check LEB 0. Then 389 * a. if LEB 0 is OK, it must be containing the most recent data; then 390 * we compare it with LEB 1, and if they are different, we copy LEB 391 * 0 to LEB 1; 392 * b. if LEB 0 is corrupted, but LEB 1 has to be OK, and we copy LEB 1 393 * to LEB 0. 394 */ 395 396 dbg_gen("check layout volume"); 397 398 /* Read both LEB 0 and LEB 1 into memory */ 399 ubi_rb_for_each_entry(rb, aeb, &av->root, u.rb) { 400 leb[aeb->lnum] = vzalloc(ubi->vtbl_size); 401 if (!leb[aeb->lnum]) { 402 err = -ENOMEM; 403 goto out_free; 404 } 405 406 err = ubi_io_read_data(ubi, leb[aeb->lnum], aeb->pnum, 0, 407 ubi->vtbl_size); 408 if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) 409 /* 410 * Scrub the PEB later. Note, -EBADMSG indicates an 411 * uncorrectable ECC error, but we have our own CRC and 412 * the data will be checked later. If the data is OK, 413 * the PEB will be scrubbed (because we set 414 * aeb->scrub). If the data is not OK, the contents of 415 * the PEB will be recovered from the second copy, and 416 * aeb->scrub will be cleared in 417 * 'ubi_add_to_av()'. 418 */ 419 aeb->scrub = 1; 420 else if (err) 421 goto out_free; 422 } 423 424 err = -EINVAL; 425 if (leb[0]) { 426 leb_corrupted[0] = vtbl_check(ubi, leb[0]); 427 if (leb_corrupted[0] < 0) 428 goto out_free; 429 } 430 431 if (!leb_corrupted[0]) { 432 /* LEB 0 is OK */ 433 if (leb[1]) 434 leb_corrupted[1] = memcmp(leb[0], leb[1], 435 ubi->vtbl_size); 436 if (leb_corrupted[1]) { 437 ubi_warn(ubi, "volume table copy #2 is corrupted"); 438 err = create_vtbl(ubi, ai, 1, leb[0]); 439 if (err) 440 goto out_free; 441 ubi_msg(ubi, "volume table was restored"); 442 } 443 444 /* Both LEB 1 and LEB 2 are OK and consistent */ 445 vfree(leb[1]); 446 return leb[0]; 447 } else { 448 /* LEB 0 is corrupted or does not exist */ 449 if (leb[1]) { 450 leb_corrupted[1] = vtbl_check(ubi, leb[1]); 451 if (leb_corrupted[1] < 0) 452 goto out_free; 453 } 454 if (leb_corrupted[1]) { 455 /* Both LEB 0 and LEB 1 are corrupted */ 456 ubi_err(ubi, "both volume tables are corrupted"); 457 goto out_free; 458 } 459 460 ubi_warn(ubi, "volume table copy #1 is corrupted"); 461 err = create_vtbl(ubi, ai, 0, leb[1]); 462 if (err) 463 goto out_free; 464 ubi_msg(ubi, "volume table was restored"); 465 466 vfree(leb[0]); 467 return leb[1]; 468 } 469 470out_free: 471 vfree(leb[0]); 472 vfree(leb[1]); 473 return ERR_PTR(err); 474} 475 476/** 477 * create_empty_lvol - create empty layout volume. 478 * @ubi: UBI device description object 479 * @ai: attaching information 480 * 481 * This function returns volume table contents in case of success and a 482 * negative error code in case of failure. 483 */ 484static struct ubi_vtbl_record *create_empty_lvol(struct ubi_device *ubi, 485 struct ubi_attach_info *ai) 486{ 487 int i; 488 struct ubi_vtbl_record *vtbl; 489 490 vtbl = vzalloc(ubi->vtbl_size); 491 if (!vtbl) 492 return ERR_PTR(-ENOMEM); 493 494 for (i = 0; i < ubi->vtbl_slots; i++) 495 memcpy(&vtbl[i], &empty_vtbl_record, UBI_VTBL_RECORD_SIZE); 496 497 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { 498 int err; 499 500 err = create_vtbl(ubi, ai, i, vtbl); 501 if (err) { 502 vfree(vtbl); 503 return ERR_PTR(err); 504 } 505 } 506 507 return vtbl; 508} 509 510/** 511 * init_volumes - initialize volume information for existing volumes. 512 * @ubi: UBI device description object 513 * @ai: scanning information 514 * @vtbl: volume table 515 * 516 * This function allocates volume description objects for existing volumes. 517 * Returns zero in case of success and a negative error code in case of 518 * failure. 519 */ 520static int init_volumes(struct ubi_device *ubi, 521 const struct ubi_attach_info *ai, 522 const struct ubi_vtbl_record *vtbl) 523{ 524 int i, err, reserved_pebs = 0; 525 struct ubi_ainf_volume *av; 526 struct ubi_volume *vol; 527 528 for (i = 0; i < ubi->vtbl_slots; i++) { 529 cond_resched(); 530 531 if (be32_to_cpu(vtbl[i].reserved_pebs) == 0) 532 continue; /* Empty record */ 533 534 vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); 535 if (!vol) 536 return -ENOMEM; 537 538 vol->reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs); 539 vol->alignment = be32_to_cpu(vtbl[i].alignment); 540 vol->data_pad = be32_to_cpu(vtbl[i].data_pad); 541 vol->upd_marker = vtbl[i].upd_marker; 542 vol->vol_type = vtbl[i].vol_type == UBI_VID_DYNAMIC ? 543 UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME; 544 vol->name_len = be16_to_cpu(vtbl[i].name_len); 545 vol->usable_leb_size = ubi->leb_size - vol->data_pad; 546 memcpy(vol->name, vtbl[i].name, vol->name_len); 547 vol->name[vol->name_len] = '\0'; 548 vol->vol_id = i; 549 550 if (vtbl[i].flags & UBI_VTBL_SKIP_CRC_CHECK_FLG) 551 vol->skip_check = 1; 552 553 if (vtbl[i].flags & UBI_VTBL_AUTORESIZE_FLG) { 554 /* Auto re-size flag may be set only for one volume */ 555 if (ubi->autoresize_vol_id != -1) { 556 ubi_err(ubi, "more than one auto-resize volume (%d and %d)", 557 ubi->autoresize_vol_id, i); 558 kfree(vol); 559 return -EINVAL; 560 } 561 562 ubi->autoresize_vol_id = i; 563 } 564 565 ubi_assert(!ubi->volumes[i]); 566 ubi->volumes[i] = vol; 567 ubi->vol_count += 1; 568 vol->ubi = ubi; 569 reserved_pebs += vol->reserved_pebs; 570 571 /* 572 * We use ubi->peb_count and not vol->reserved_pebs because 573 * we want to keep the code simple. Otherwise we'd have to 574 * resize/check the bitmap upon volume resize too. 575 * Allocating a few bytes more does not hurt. 576 */ 577 err = ubi_fastmap_init_checkmap(vol, ubi->peb_count); 578 if (err) 579 return err; 580 581 /* 582 * In case of dynamic volume UBI knows nothing about how many 583 * data is stored there. So assume the whole volume is used. 584 */ 585 if (vol->vol_type == UBI_DYNAMIC_VOLUME) { 586 vol->used_ebs = vol->reserved_pebs; 587 vol->last_eb_bytes = vol->usable_leb_size; 588 vol->used_bytes = 589 (long long)vol->used_ebs * vol->usable_leb_size; 590 continue; 591 } 592 593 /* Static volumes only */ 594 av = ubi_find_av(ai, i); 595 if (!av || !av->leb_count) { 596 /* 597 * No eraseblocks belonging to this volume found. We 598 * don't actually know whether this static volume is 599 * completely corrupted or just contains no data. And 600 * we cannot know this as long as data size is not 601 * stored on flash. So we just assume the volume is 602 * empty. FIXME: this should be handled. 603 */ 604 continue; 605 } 606 607 if (av->leb_count != av->used_ebs) { 608 /* 609 * We found a static volume which misses several 610 * eraseblocks. Treat it as corrupted. 611 */ 612 ubi_warn(ubi, "static volume %d misses %d LEBs - corrupted", 613 av->vol_id, av->used_ebs - av->leb_count); 614 vol->corrupted = 1; 615 continue; 616 } 617 618 vol->used_ebs = av->used_ebs; 619 vol->used_bytes = 620 (long long)(vol->used_ebs - 1) * vol->usable_leb_size; 621 vol->used_bytes += av->last_data_size; 622 vol->last_eb_bytes = av->last_data_size; 623 } 624 625 /* And add the layout volume */ 626 vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); 627 if (!vol) 628 return -ENOMEM; 629 630 vol->reserved_pebs = UBI_LAYOUT_VOLUME_EBS; 631 vol->alignment = UBI_LAYOUT_VOLUME_ALIGN; 632 vol->vol_type = UBI_DYNAMIC_VOLUME; 633 vol->name_len = sizeof(UBI_LAYOUT_VOLUME_NAME) - 1; 634 memcpy(vol->name, UBI_LAYOUT_VOLUME_NAME, vol->name_len + 1); 635 vol->usable_leb_size = ubi->leb_size; 636 vol->used_ebs = vol->reserved_pebs; 637 vol->last_eb_bytes = vol->reserved_pebs; 638 vol->used_bytes = 639 (long long)vol->used_ebs * (ubi->leb_size - vol->data_pad); 640 vol->vol_id = UBI_LAYOUT_VOLUME_ID; 641 vol->ref_count = 1; 642 643 ubi_assert(!ubi->volumes[i]); 644 ubi->volumes[vol_id2idx(ubi, vol->vol_id)] = vol; 645 reserved_pebs += vol->reserved_pebs; 646 ubi->vol_count += 1; 647 vol->ubi = ubi; 648 err = ubi_fastmap_init_checkmap(vol, UBI_LAYOUT_VOLUME_EBS); 649 if (err) 650 return err; 651 652 if (reserved_pebs > ubi->avail_pebs) { 653 ubi_err(ubi, "not enough PEBs, required %d, available %d", 654 reserved_pebs, ubi->avail_pebs); 655 if (ubi->corr_peb_count) 656 ubi_err(ubi, "%d PEBs are corrupted and not used", 657 ubi->corr_peb_count); 658 return -ENOSPC; 659 } 660 ubi->rsvd_pebs += reserved_pebs; 661 ubi->avail_pebs -= reserved_pebs; 662 663 return 0; 664} 665 666/** 667 * check_av - check volume attaching information. 668 * @vol: UBI volume description object 669 * @av: volume attaching information 670 * 671 * This function returns zero if the volume attaching information is consistent 672 * to the data read from the volume tabla, and %-EINVAL if not. 673 */ 674static int check_av(const struct ubi_volume *vol, 675 const struct ubi_ainf_volume *av) 676{ 677 int err; 678 679 if (av->highest_lnum >= vol->reserved_pebs) { 680 err = 1; 681 goto bad; 682 } 683 if (av->leb_count > vol->reserved_pebs) { 684 err = 2; 685 goto bad; 686 } 687 if (av->vol_type != vol->vol_type) { 688 err = 3; 689 goto bad; 690 } 691 if (av->used_ebs > vol->reserved_pebs) { 692 err = 4; 693 goto bad; 694 } 695 if (av->data_pad != vol->data_pad) { 696 err = 5; 697 goto bad; 698 } 699 return 0; 700 701bad: 702 ubi_err(vol->ubi, "bad attaching information, error %d", err); 703 ubi_dump_av(av); 704 ubi_dump_vol_info(vol); 705 return -EINVAL; 706} 707 708/** 709 * check_attaching_info - check that attaching information. 710 * @ubi: UBI device description object 711 * @ai: attaching information 712 * 713 * Even though we protect on-flash data by CRC checksums, we still don't trust 714 * the media. This function ensures that attaching information is consistent to 715 * the information read from the volume table. Returns zero if the attaching 716 * information is OK and %-EINVAL if it is not. 717 */ 718static int check_attaching_info(const struct ubi_device *ubi, 719 struct ubi_attach_info *ai) 720{ 721 int err, i; 722 struct ubi_ainf_volume *av; 723 struct ubi_volume *vol; 724 725 if (ai->vols_found > UBI_INT_VOL_COUNT + ubi->vtbl_slots) { 726 ubi_err(ubi, "found %d volumes while attaching, maximum is %d + %d", 727 ai->vols_found, UBI_INT_VOL_COUNT, ubi->vtbl_slots); 728 return -EINVAL; 729 } 730 731 if (ai->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT && 732 ai->highest_vol_id < UBI_INTERNAL_VOL_START) { 733 ubi_err(ubi, "too large volume ID %d found", 734 ai->highest_vol_id); 735 return -EINVAL; 736 } 737 738 for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) { 739 cond_resched(); 740 741 av = ubi_find_av(ai, i); 742 vol = ubi->volumes[i]; 743 if (!vol) { 744 if (av) 745 ubi_remove_av(ai, av); 746 continue; 747 } 748 749 if (vol->reserved_pebs == 0) { 750 ubi_assert(i < ubi->vtbl_slots); 751 752 if (!av) 753 continue; 754 755 /* 756 * During attaching we found a volume which does not 757 * exist according to the information in the volume 758 * table. This must have happened due to an unclean 759 * reboot while the volume was being removed. Discard 760 * these eraseblocks. 761 */ 762 ubi_msg(ubi, "finish volume %d removal", av->vol_id); 763 ubi_remove_av(ai, av); 764 } else if (av) { 765 err = check_av(vol, av); 766 if (err) 767 return err; 768 } 769 } 770 771 return 0; 772} 773 774/** 775 * ubi_read_volume_table - read the volume table. 776 * @ubi: UBI device description object 777 * @ai: attaching information 778 * 779 * This function reads volume table, checks it, recover from errors if needed, 780 * or creates it if needed. Returns zero in case of success and a negative 781 * error code in case of failure. 782 */ 783int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai) 784{ 785 int err; 786 struct ubi_ainf_volume *av; 787 788 empty_vtbl_record.crc = cpu_to_be32(0xf116c36b); 789 790 /* 791 * The number of supported volumes is limited by the eraseblock size 792 * and by the UBI_MAX_VOLUMES constant. 793 */ 794 795 if (ubi->leb_size < UBI_VTBL_RECORD_SIZE) { 796 ubi_err(ubi, "LEB size too small for a volume record"); 797 return -EINVAL; 798 } 799 800 ubi->vtbl_slots = ubi->leb_size / UBI_VTBL_RECORD_SIZE; 801 if (ubi->vtbl_slots > UBI_MAX_VOLUMES) 802 ubi->vtbl_slots = UBI_MAX_VOLUMES; 803 804 ubi->vtbl_size = ubi->vtbl_slots * UBI_VTBL_RECORD_SIZE; 805 ubi->vtbl_size = ALIGN(ubi->vtbl_size, ubi->min_io_size); 806 807 av = ubi_find_av(ai, UBI_LAYOUT_VOLUME_ID); 808 if (!av) { 809 /* 810 * No logical eraseblocks belonging to the layout volume were 811 * found. This could mean that the flash is just empty. In 812 * this case we create empty layout volume. 813 * 814 * But if flash is not empty this must be a corruption or the 815 * MTD device just contains garbage. 816 */ 817 if (ai->is_empty) { 818 ubi->vtbl = create_empty_lvol(ubi, ai); 819 if (IS_ERR(ubi->vtbl)) 820 return PTR_ERR(ubi->vtbl); 821 } else { 822 ubi_err(ubi, "the layout volume was not found"); 823 return -EINVAL; 824 } 825 } else { 826 if (av->leb_count > UBI_LAYOUT_VOLUME_EBS) { 827 /* This must not happen with proper UBI images */ 828 ubi_err(ubi, "too many LEBs (%d) in layout volume", 829 av->leb_count); 830 return -EINVAL; 831 } 832 833 ubi->vtbl = process_lvol(ubi, ai, av); 834 if (IS_ERR(ubi->vtbl)) 835 return PTR_ERR(ubi->vtbl); 836 } 837 838 ubi->avail_pebs = ubi->good_peb_count - ubi->corr_peb_count; 839 840 /* 841 * The layout volume is OK, initialize the corresponding in-RAM data 842 * structures. 843 */ 844 err = init_volumes(ubi, ai, ubi->vtbl); 845 if (err) 846 goto out_free; 847 848 /* 849 * Make sure that the attaching information is consistent to the 850 * information stored in the volume table. 851 */ 852 err = check_attaching_info(ubi, ai); 853 if (err) 854 goto out_free; 855 856 return 0; 857 858out_free: 859 vfree(ubi->vtbl); 860 ubi_free_all_volumes(ubi); 861 return err; 862} 863 864/** 865 * self_vtbl_check - check volume table. 866 * @ubi: UBI device description object 867 */ 868static void self_vtbl_check(const struct ubi_device *ubi) 869{ 870 if (!ubi_dbg_chk_gen(ubi)) 871 return; 872 873 if (vtbl_check(ubi, ubi->vtbl)) { 874 ubi_err(ubi, "self-check failed"); 875 BUG(); 876 } 877} 878