1/* 2 * Copyright (c) International Business Machines Corp., 2006 3 * Copyright (c) Nokia Corporation, 2006, 2007 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See 13 * the GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 * 19 * Author: Artem Bityutskiy (���������������� ����������) 20 */ 21 22/* 23 * This file includes volume table manipulation code. The volume table is an 24 * on-flash table containing volume meta-data like name, number of reserved 25 * physical eraseblocks, type, etc. The volume table is stored in the so-called 26 * "layout volume". 27 * 28 * The layout volume is an internal volume which is organized as follows. It 29 * consists of two logical eraseblocks - LEB 0 and LEB 1. Each logical 30 * eraseblock stores one volume table copy, i.e. LEB 0 and LEB 1 duplicate each 31 * other. This redundancy guarantees robustness to unclean reboots. The volume 32 * table is basically an array of volume table records. Each record contains 33 * full information about the volume and protected by a CRC checksum. Note, 34 * nowadays we use the atomic LEB change operation when updating the volume 35 * table, so we do not really need 2 LEBs anymore, but we preserve the older 36 * design for the backward compatibility reasons. 37 * 38 * When the volume table is changed, it is first changed in RAM. Then LEB 0 is 39 * erased, and the updated volume table is written back to LEB 0. Then same for 40 * LEB 1. This scheme guarantees recoverability from unclean reboots. 41 * 42 * In this UBI implementation the on-flash volume table does not contain any 43 * information about how much data static volumes contain. 44 * 45 * But it would still be beneficial to store this information in the volume 46 * table. For example, suppose we have a static volume X, and all its physical 47 * eraseblocks became bad for some reasons. Suppose we are attaching the 48 * corresponding MTD device, for some reason we find no logical eraseblocks 49 * corresponding to the volume X. According to the volume table volume X does 50 * exist. So we don't know whether it is just empty or all its physical 51 * eraseblocks went bad. So we cannot alarm the user properly. 52 * 53 * The volume table also stores so-called "update marker", which is used for 54 * volume updates. Before updating the volume, the update marker is set, and 55 * after the update operation is finished, the update marker is cleared. So if 56 * the update operation was interrupted (e.g. by an unclean reboot) - the 57 * update marker is still there and we know that the volume's contents is 58 * damaged. 59 */ 60 61#include <linux/crc32.h> 62#include <linux/err.h> 63#include <linux/slab.h> 64#include <asm/div64.h> 65#include "ubi.h" 66 67static void self_vtbl_check(const struct ubi_device *ubi); 68 69/* Empty volume table record */ 70static struct ubi_vtbl_record empty_vtbl_record; 71 72/** 73 * ubi_update_layout_vol - helper for updatting layout volumes on flash 74 * @ubi: UBI device description object 75 */ 76static int ubi_update_layout_vol(struct ubi_device *ubi) 77{ 78 struct ubi_volume *layout_vol; 79 int i, err; 80 81 layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)]; 82 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { 83 err = ubi_eba_atomic_leb_change(ubi, layout_vol, i, ubi->vtbl, 84 ubi->vtbl_size); 85 if (err) 86 return err; 87 } 88 89 return 0; 90} 91 92/** 93 * ubi_change_vtbl_record - change volume table record. 94 * @ubi: UBI device description object 95 * @idx: table index to change 96 * @vtbl_rec: new volume table record 97 * 98 * This function changes volume table record @idx. If @vtbl_rec is %NULL, empty 99 * volume table record is written. The caller does not have to calculate CRC of 100 * the record as it is done by this function. Returns zero in case of success 101 * and a negative error code in case of failure. 102 */ 103int ubi_change_vtbl_record(struct ubi_device *ubi, int idx, 104 struct ubi_vtbl_record *vtbl_rec) 105{ 106 int err; 107 uint32_t crc; 108 109 ubi_assert(idx >= 0 && idx < ubi->vtbl_slots); 110 111 if (!vtbl_rec) 112 vtbl_rec = &empty_vtbl_record; 113 else { 114 crc = crc32(UBI_CRC32_INIT, vtbl_rec, UBI_VTBL_RECORD_SIZE_CRC); 115 vtbl_rec->crc = cpu_to_be32(crc); 116 } 117 118 memcpy(&ubi->vtbl[idx], vtbl_rec, sizeof(struct ubi_vtbl_record)); 119 err = ubi_update_layout_vol(ubi); 120 121 self_vtbl_check(ubi); 122 return err ? err : 0; 123} 124 125/** 126 * ubi_vtbl_rename_volumes - rename UBI volumes in the volume table. 127 * @ubi: UBI device description object 128 * @rename_list: list of &struct ubi_rename_entry objects 129 * 130 * This function re-names multiple volumes specified in @req in the volume 131 * table. Returns zero in case of success and a negative error code in case of 132 * failure. 133 */ 134int ubi_vtbl_rename_volumes(struct ubi_device *ubi, 135 struct list_head *rename_list) 136{ 137 struct ubi_rename_entry *re; 138 139 list_for_each_entry(re, rename_list, list) { 140 uint32_t crc; 141 struct ubi_volume *vol = re->desc->vol; 142 struct ubi_vtbl_record *vtbl_rec = &ubi->vtbl[vol->vol_id]; 143 144 if (re->remove) { 145 memcpy(vtbl_rec, &empty_vtbl_record, 146 sizeof(struct ubi_vtbl_record)); 147 continue; 148 } 149 150 vtbl_rec->name_len = cpu_to_be16(re->new_name_len); 151 memcpy(vtbl_rec->name, re->new_name, re->new_name_len); 152 memset(vtbl_rec->name + re->new_name_len, 0, 153 UBI_VOL_NAME_MAX + 1 - re->new_name_len); 154 crc = crc32(UBI_CRC32_INIT, vtbl_rec, 155 UBI_VTBL_RECORD_SIZE_CRC); 156 vtbl_rec->crc = cpu_to_be32(crc); 157 } 158 159 return ubi_update_layout_vol(ubi); 160} 161 162/** 163 * vtbl_check - check if volume table is not corrupted and sensible. 164 * @ubi: UBI device description object 165 * @vtbl: volume table 166 * 167 * This function returns zero if @vtbl is all right, %1 if CRC is incorrect, 168 * and %-EINVAL if it contains inconsistent data. 169 */ 170static int vtbl_check(const struct ubi_device *ubi, 171 const struct ubi_vtbl_record *vtbl) 172{ 173 int i, n, reserved_pebs, alignment, data_pad, vol_type, name_len; 174 int upd_marker, err; 175 uint32_t crc; 176 const char *name; 177 178 for (i = 0; i < ubi->vtbl_slots; i++) { 179 cond_resched(); 180 181 reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs); 182 alignment = be32_to_cpu(vtbl[i].alignment); 183 data_pad = be32_to_cpu(vtbl[i].data_pad); 184 upd_marker = vtbl[i].upd_marker; 185 vol_type = vtbl[i].vol_type; 186 name_len = be16_to_cpu(vtbl[i].name_len); 187 name = &vtbl[i].name[0]; 188 189 crc = crc32(UBI_CRC32_INIT, &vtbl[i], UBI_VTBL_RECORD_SIZE_CRC); 190 if (be32_to_cpu(vtbl[i].crc) != crc) { 191 ubi_err(ubi, "bad CRC at record %u: %#08x, not %#08x", 192 i, crc, be32_to_cpu(vtbl[i].crc)); 193 ubi_dump_vtbl_record(&vtbl[i], i); 194 return 1; 195 } 196 197 if (reserved_pebs == 0) { 198 if (memcmp(&vtbl[i], &empty_vtbl_record, 199 UBI_VTBL_RECORD_SIZE)) { 200 err = 2; 201 goto bad; 202 } 203 continue; 204 } 205 206 if (reserved_pebs < 0 || alignment < 0 || data_pad < 0 || 207 name_len < 0) { 208 err = 3; 209 goto bad; 210 } 211 212 if (alignment > ubi->leb_size || alignment == 0) { 213 err = 4; 214 goto bad; 215 } 216 217 n = alignment & (ubi->min_io_size - 1); 218 if (alignment != 1 && n) { 219 err = 5; 220 goto bad; 221 } 222 223 n = ubi->leb_size % alignment; 224 if (data_pad != n) { 225 ubi_err(ubi, "bad data_pad, has to be %d", n); 226 err = 6; 227 goto bad; 228 } 229 230 if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) { 231 err = 7; 232 goto bad; 233 } 234 235 if (upd_marker != 0 && upd_marker != 1) { 236 err = 8; 237 goto bad; 238 } 239 240 if (reserved_pebs > ubi->good_peb_count) { 241 ubi_err(ubi, "too large reserved_pebs %d, good PEBs %d", 242 reserved_pebs, ubi->good_peb_count); 243 err = 9; 244 goto bad; 245 } 246 247 if (name_len > UBI_VOL_NAME_MAX) { 248 err = 10; 249 goto bad; 250 } 251 252 if (name[0] == '\0') { 253 err = 11; 254 goto bad; 255 } 256 257 if (name_len != strnlen(name, name_len + 1)) { 258 err = 12; 259 goto bad; 260 } 261 } 262 263 /* Checks that all names are unique */ 264 for (i = 0; i < ubi->vtbl_slots - 1; i++) { 265 for (n = i + 1; n < ubi->vtbl_slots; n++) { 266 int len1 = be16_to_cpu(vtbl[i].name_len); 267 int len2 = be16_to_cpu(vtbl[n].name_len); 268 269 if (len1 > 0 && len1 == len2 && 270 !strncmp(vtbl[i].name, vtbl[n].name, len1)) { 271 ubi_err(ubi, "volumes %d and %d have the same name \"%s\"", 272 i, n, vtbl[i].name); 273 ubi_dump_vtbl_record(&vtbl[i], i); 274 ubi_dump_vtbl_record(&vtbl[n], n); 275 return -EINVAL; 276 } 277 } 278 } 279 280 return 0; 281 282bad: 283 ubi_err(ubi, "volume table check failed: record %d, error %d", i, err); 284 ubi_dump_vtbl_record(&vtbl[i], i); 285 return -EINVAL; 286} 287 288/** 289 * create_vtbl - create a copy of volume table. 290 * @ubi: UBI device description object 291 * @ai: attaching information 292 * @copy: number of the volume table copy 293 * @vtbl: contents of the volume table 294 * 295 * This function returns zero in case of success and a negative error code in 296 * case of failure. 297 */ 298static int create_vtbl(struct ubi_device *ubi, struct ubi_attach_info *ai, 299 int copy, void *vtbl) 300{ 301 int err, tries = 0; 302 struct ubi_vid_hdr *vid_hdr; 303 struct ubi_ainf_peb *new_aeb; 304 305 dbg_gen("create volume table (copy #%d)", copy + 1); 306 307 vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL); 308 if (!vid_hdr) 309 return -ENOMEM; 310 311retry: 312 new_aeb = ubi_early_get_peb(ubi, ai); 313 if (IS_ERR(new_aeb)) { 314 err = PTR_ERR(new_aeb); 315 goto out_free; 316 } 317 318 vid_hdr->vol_type = UBI_LAYOUT_VOLUME_TYPE; 319 vid_hdr->vol_id = cpu_to_be32(UBI_LAYOUT_VOLUME_ID); 320 vid_hdr->compat = UBI_LAYOUT_VOLUME_COMPAT; 321 vid_hdr->data_size = vid_hdr->used_ebs = 322 vid_hdr->data_pad = cpu_to_be32(0); 323 vid_hdr->lnum = cpu_to_be32(copy); 324 vid_hdr->sqnum = cpu_to_be64(++ai->max_sqnum); 325 326 /* The EC header is already there, write the VID header */ 327 err = ubi_io_write_vid_hdr(ubi, new_aeb->pnum, vid_hdr); 328 if (err) 329 goto write_error; 330 331 /* Write the layout volume contents */ 332 err = ubi_io_write_data(ubi, vtbl, new_aeb->pnum, 0, ubi->vtbl_size); 333 if (err) 334 goto write_error; 335 336 /* 337 * And add it to the attaching information. Don't delete the old version 338 * of this LEB as it will be deleted and freed in 'ubi_add_to_av()'. 339 */ 340 err = ubi_add_to_av(ubi, ai, new_aeb->pnum, new_aeb->ec, vid_hdr, 0); 341 kmem_cache_free(ai->aeb_slab_cache, new_aeb); 342 ubi_free_vid_hdr(ubi, vid_hdr); 343 return err; 344 345write_error: 346 if (err == -EIO && ++tries <= 5) { 347 /* 348 * Probably this physical eraseblock went bad, try to pick 349 * another one. 350 */ 351 list_add(&new_aeb->u.list, &ai->erase); 352 goto retry; 353 } 354 kmem_cache_free(ai->aeb_slab_cache, new_aeb); 355out_free: 356 ubi_free_vid_hdr(ubi, vid_hdr); 357 return err; 358 359} 360 361/** 362 * process_lvol - process the layout volume. 363 * @ubi: UBI device description object 364 * @ai: attaching information 365 * @av: layout volume attaching information 366 * 367 * This function is responsible for reading the layout volume, ensuring it is 368 * not corrupted, and recovering from corruptions if needed. Returns volume 369 * table in case of success and a negative error code in case of failure. 370 */ 371static struct ubi_vtbl_record *process_lvol(struct ubi_device *ubi, 372 struct ubi_attach_info *ai, 373 struct ubi_ainf_volume *av) 374{ 375 int err; 376 struct rb_node *rb; 377 struct ubi_ainf_peb *aeb; 378 struct ubi_vtbl_record *leb[UBI_LAYOUT_VOLUME_EBS] = { NULL, NULL }; 379 int leb_corrupted[UBI_LAYOUT_VOLUME_EBS] = {1, 1}; 380 381 /* 382 * UBI goes through the following steps when it changes the layout 383 * volume: 384 * a. erase LEB 0; 385 * b. write new data to LEB 0; 386 * c. erase LEB 1; 387 * d. write new data to LEB 1. 388 * 389 * Before the change, both LEBs contain the same data. 390 * 391 * Due to unclean reboots, the contents of LEB 0 may be lost, but there 392 * should LEB 1. So it is OK if LEB 0 is corrupted while LEB 1 is not. 393 * Similarly, LEB 1 may be lost, but there should be LEB 0. And 394 * finally, unclean reboots may result in a situation when neither LEB 395 * 0 nor LEB 1 are corrupted, but they are different. In this case, LEB 396 * 0 contains more recent information. 397 * 398 * So the plan is to first check LEB 0. Then 399 * a. if LEB 0 is OK, it must be containing the most recent data; then 400 * we compare it with LEB 1, and if they are different, we copy LEB 401 * 0 to LEB 1; 402 * b. if LEB 0 is corrupted, but LEB 1 has to be OK, and we copy LEB 1 403 * to LEB 0. 404 */ 405 406 dbg_gen("check layout volume"); 407 408 /* Read both LEB 0 and LEB 1 into memory */ 409 ubi_rb_for_each_entry(rb, aeb, &av->root, u.rb) { 410 leb[aeb->lnum] = vzalloc(ubi->vtbl_size); 411 if (!leb[aeb->lnum]) { 412 err = -ENOMEM; 413 goto out_free; 414 } 415 416 err = ubi_io_read_data(ubi, leb[aeb->lnum], aeb->pnum, 0, 417 ubi->vtbl_size); 418 if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) 419 /* 420 * Scrub the PEB later. Note, -EBADMSG indicates an 421 * uncorrectable ECC error, but we have our own CRC and 422 * the data will be checked later. If the data is OK, 423 * the PEB will be scrubbed (because we set 424 * aeb->scrub). If the data is not OK, the contents of 425 * the PEB will be recovered from the second copy, and 426 * aeb->scrub will be cleared in 427 * 'ubi_add_to_av()'. 428 */ 429 aeb->scrub = 1; 430 else if (err) 431 goto out_free; 432 } 433 434 err = -EINVAL; 435 if (leb[0]) { 436 leb_corrupted[0] = vtbl_check(ubi, leb[0]); 437 if (leb_corrupted[0] < 0) 438 goto out_free; 439 } 440 441 if (!leb_corrupted[0]) { 442 /* LEB 0 is OK */ 443 if (leb[1]) 444 leb_corrupted[1] = memcmp(leb[0], leb[1], 445 ubi->vtbl_size); 446 if (leb_corrupted[1]) { 447 ubi_warn(ubi, "volume table copy #2 is corrupted"); 448 err = create_vtbl(ubi, ai, 1, leb[0]); 449 if (err) 450 goto out_free; 451 ubi_msg(ubi, "volume table was restored"); 452 } 453 454 /* Both LEB 1 and LEB 2 are OK and consistent */ 455 vfree(leb[1]); 456 return leb[0]; 457 } else { 458 /* LEB 0 is corrupted or does not exist */ 459 if (leb[1]) { 460 leb_corrupted[1] = vtbl_check(ubi, leb[1]); 461 if (leb_corrupted[1] < 0) 462 goto out_free; 463 } 464 if (leb_corrupted[1]) { 465 /* Both LEB 0 and LEB 1 are corrupted */ 466 ubi_err(ubi, "both volume tables are corrupted"); 467 goto out_free; 468 } 469 470 ubi_warn(ubi, "volume table copy #1 is corrupted"); 471 err = create_vtbl(ubi, ai, 0, leb[1]); 472 if (err) 473 goto out_free; 474 ubi_msg(ubi, "volume table was restored"); 475 476 vfree(leb[0]); 477 return leb[1]; 478 } 479 480out_free: 481 vfree(leb[0]); 482 vfree(leb[1]); 483 return ERR_PTR(err); 484} 485 486/** 487 * create_empty_lvol - create empty layout volume. 488 * @ubi: UBI device description object 489 * @ai: attaching information 490 * 491 * This function returns volume table contents in case of success and a 492 * negative error code in case of failure. 493 */ 494static struct ubi_vtbl_record *create_empty_lvol(struct ubi_device *ubi, 495 struct ubi_attach_info *ai) 496{ 497 int i; 498 struct ubi_vtbl_record *vtbl; 499 500 vtbl = vzalloc(ubi->vtbl_size); 501 if (!vtbl) 502 return ERR_PTR(-ENOMEM); 503 504 for (i = 0; i < ubi->vtbl_slots; i++) 505 memcpy(&vtbl[i], &empty_vtbl_record, UBI_VTBL_RECORD_SIZE); 506 507 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { 508 int err; 509 510 err = create_vtbl(ubi, ai, i, vtbl); 511 if (err) { 512 vfree(vtbl); 513 return ERR_PTR(err); 514 } 515 } 516 517 return vtbl; 518} 519 520/** 521 * init_volumes - initialize volume information for existing volumes. 522 * @ubi: UBI device description object 523 * @ai: scanning information 524 * @vtbl: volume table 525 * 526 * This function allocates volume description objects for existing volumes. 527 * Returns zero in case of success and a negative error code in case of 528 * failure. 529 */ 530static int init_volumes(struct ubi_device *ubi, 531 const struct ubi_attach_info *ai, 532 const struct ubi_vtbl_record *vtbl) 533{ 534 int i, reserved_pebs = 0; 535 struct ubi_ainf_volume *av; 536 struct ubi_volume *vol; 537 538 for (i = 0; i < ubi->vtbl_slots; i++) { 539 cond_resched(); 540 541 if (be32_to_cpu(vtbl[i].reserved_pebs) == 0) 542 continue; /* Empty record */ 543 544 vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); 545 if (!vol) 546 return -ENOMEM; 547 548 vol->reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs); 549 vol->alignment = be32_to_cpu(vtbl[i].alignment); 550 vol->data_pad = be32_to_cpu(vtbl[i].data_pad); 551 vol->upd_marker = vtbl[i].upd_marker; 552 vol->vol_type = vtbl[i].vol_type == UBI_VID_DYNAMIC ? 553 UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME; 554 vol->name_len = be16_to_cpu(vtbl[i].name_len); 555 vol->usable_leb_size = ubi->leb_size - vol->data_pad; 556 memcpy(vol->name, vtbl[i].name, vol->name_len); 557 vol->name[vol->name_len] = '\0'; 558 vol->vol_id = i; 559 560 if (vtbl[i].flags & UBI_VTBL_AUTORESIZE_FLG) { 561 /* Auto re-size flag may be set only for one volume */ 562 if (ubi->autoresize_vol_id != -1) { 563 ubi_err(ubi, "more than one auto-resize volume (%d and %d)", 564 ubi->autoresize_vol_id, i); 565 kfree(vol); 566 return -EINVAL; 567 } 568 569 ubi->autoresize_vol_id = i; 570 } 571 572 ubi_assert(!ubi->volumes[i]); 573 ubi->volumes[i] = vol; 574 ubi->vol_count += 1; 575 vol->ubi = ubi; 576 reserved_pebs += vol->reserved_pebs; 577 578 /* 579 * In case of dynamic volume UBI knows nothing about how many 580 * data is stored there. So assume the whole volume is used. 581 */ 582 if (vol->vol_type == UBI_DYNAMIC_VOLUME) { 583 vol->used_ebs = vol->reserved_pebs; 584 vol->last_eb_bytes = vol->usable_leb_size; 585 vol->used_bytes = 586 (long long)vol->used_ebs * vol->usable_leb_size; 587 continue; 588 } 589 590 /* Static volumes only */ 591 av = ubi_find_av(ai, i); 592 if (!av || !av->leb_count) { 593 /* 594 * No eraseblocks belonging to this volume found. We 595 * don't actually know whether this static volume is 596 * completely corrupted or just contains no data. And 597 * we cannot know this as long as data size is not 598 * stored on flash. So we just assume the volume is 599 * empty. FIXME: this should be handled. 600 */ 601 continue; 602 } 603 604 if (av->leb_count != av->used_ebs) { 605 /* 606 * We found a static volume which misses several 607 * eraseblocks. Treat it as corrupted. 608 */ 609 ubi_warn(ubi, "static volume %d misses %d LEBs - corrupted", 610 av->vol_id, av->used_ebs - av->leb_count); 611 vol->corrupted = 1; 612 continue; 613 } 614 615 vol->used_ebs = av->used_ebs; 616 vol->used_bytes = 617 (long long)(vol->used_ebs - 1) * vol->usable_leb_size; 618 vol->used_bytes += av->last_data_size; 619 vol->last_eb_bytes = av->last_data_size; 620 } 621 622 /* And add the layout volume */ 623 vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); 624 if (!vol) 625 return -ENOMEM; 626 627 vol->reserved_pebs = UBI_LAYOUT_VOLUME_EBS; 628 vol->alignment = UBI_LAYOUT_VOLUME_ALIGN; 629 vol->vol_type = UBI_DYNAMIC_VOLUME; 630 vol->name_len = sizeof(UBI_LAYOUT_VOLUME_NAME) - 1; 631 memcpy(vol->name, UBI_LAYOUT_VOLUME_NAME, vol->name_len + 1); 632 vol->usable_leb_size = ubi->leb_size; 633 vol->used_ebs = vol->reserved_pebs; 634 vol->last_eb_bytes = vol->reserved_pebs; 635 vol->used_bytes = 636 (long long)vol->used_ebs * (ubi->leb_size - vol->data_pad); 637 vol->vol_id = UBI_LAYOUT_VOLUME_ID; 638 vol->ref_count = 1; 639 640 ubi_assert(!ubi->volumes[i]); 641 ubi->volumes[vol_id2idx(ubi, vol->vol_id)] = vol; 642 reserved_pebs += vol->reserved_pebs; 643 ubi->vol_count += 1; 644 vol->ubi = ubi; 645 646 if (reserved_pebs > ubi->avail_pebs) { 647 ubi_err(ubi, "not enough PEBs, required %d, available %d", 648 reserved_pebs, ubi->avail_pebs); 649 if (ubi->corr_peb_count) 650 ubi_err(ubi, "%d PEBs are corrupted and not used", 651 ubi->corr_peb_count); 652 return -ENOSPC; 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 */ 668static 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 695bad: 696 ubi_err(vol->ubi, "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 */ 712static 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(ubi, "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(ubi, "too large volume ID %d found", 728 ai->highest_vol_id); 729 return -EINVAL; 730 } 731 732 for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) { 733 cond_resched(); 734 735 av = ubi_find_av(ai, i); 736 vol = ubi->volumes[i]; 737 if (!vol) { 738 if (av) 739 ubi_remove_av(ai, av); 740 continue; 741 } 742 743 if (vol->reserved_pebs == 0) { 744 ubi_assert(i < ubi->vtbl_slots); 745 746 if (!av) 747 continue; 748 749 /* 750 * During attaching we found a volume which does not 751 * exist according to the information in the volume 752 * table. This must have happened due to an unclean 753 * reboot while the volume was being removed. Discard 754 * these eraseblocks. 755 */ 756 ubi_msg(ubi, "finish volume %d removal", av->vol_id); 757 ubi_remove_av(ai, av); 758 } else if (av) { 759 err = check_av(vol, av); 760 if (err) 761 return err; 762 } 763 } 764 765 return 0; 766} 767 768/** 769 * ubi_read_volume_table - read the volume table. 770 * @ubi: UBI device description object 771 * @ai: attaching information 772 * 773 * This function reads volume table, checks it, recover from errors if needed, 774 * or creates it if needed. Returns zero in case of success and a negative 775 * error code in case of failure. 776 */ 777int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai) 778{ 779 int i, err; 780 struct ubi_ainf_volume *av; 781 782 empty_vtbl_record.crc = cpu_to_be32(0xf116c36b); 783 784 /* 785 * The number of supported volumes is limited by the eraseblock size 786 * and by the UBI_MAX_VOLUMES constant. 787 */ 788 ubi->vtbl_slots = ubi->leb_size / UBI_VTBL_RECORD_SIZE; 789 if (ubi->vtbl_slots > UBI_MAX_VOLUMES) 790 ubi->vtbl_slots = UBI_MAX_VOLUMES; 791 792 ubi->vtbl_size = ubi->vtbl_slots * UBI_VTBL_RECORD_SIZE; 793 ubi->vtbl_size = ALIGN(ubi->vtbl_size, ubi->min_io_size); 794 795 av = ubi_find_av(ai, UBI_LAYOUT_VOLUME_ID); 796 if (!av) { 797 /* 798 * No logical eraseblocks belonging to the layout volume were 799 * found. This could mean that the flash is just empty. In 800 * this case we create empty layout volume. 801 * 802 * But if flash is not empty this must be a corruption or the 803 * MTD device just contains garbage. 804 */ 805 if (ai->is_empty) { 806 ubi->vtbl = create_empty_lvol(ubi, ai); 807 if (IS_ERR(ubi->vtbl)) 808 return PTR_ERR(ubi->vtbl); 809 } else { 810 ubi_err(ubi, "the layout volume was not found"); 811 return -EINVAL; 812 } 813 } else { 814 if (av->leb_count > UBI_LAYOUT_VOLUME_EBS) { 815 /* This must not happen with proper UBI images */ 816 ubi_err(ubi, "too many LEBs (%d) in layout volume", 817 av->leb_count); 818 return -EINVAL; 819 } 820 821 ubi->vtbl = process_lvol(ubi, ai, av); 822 if (IS_ERR(ubi->vtbl)) 823 return PTR_ERR(ubi->vtbl); 824 } 825 826 ubi->avail_pebs = ubi->good_peb_count - ubi->corr_peb_count; 827 828 /* 829 * The layout volume is OK, initialize the corresponding in-RAM data 830 * structures. 831 */ 832 err = init_volumes(ubi, ai, ubi->vtbl); 833 if (err) 834 goto out_free; 835 836 /* 837 * Make sure that the attaching information is consistent to the 838 * information stored in the volume table. 839 */ 840 err = check_attaching_info(ubi, ai); 841 if (err) 842 goto out_free; 843 844 return 0; 845 846out_free: 847 vfree(ubi->vtbl); 848 for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) { 849 kfree(ubi->volumes[i]); 850 ubi->volumes[i] = NULL; 851 } 852 return err; 853} 854 855/** 856 * self_vtbl_check - check volume table. 857 * @ubi: UBI device description object 858 */ 859static void self_vtbl_check(const struct ubi_device *ubi) 860{ 861 if (!ubi_dbg_chk_gen(ubi)) 862 return; 863 864 if (vtbl_check(ubi, ubi->vtbl)) { 865 ubi_err(ubi, "self-check failed"); 866 BUG(); 867 } 868} 869