| 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 (Битюцкий Артём) |
| 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 | |
| 54 | static void self_vtbl_check(const struct ubi_device *ubi); |
| 55 | |
| 56 | /* Empty volume table record */ |
| 57 | static 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 | */ |
| 63 | static 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 | */ |
| 90 | int 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 | */ |
| 121 | int 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 | */ |
| 157 | static 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 | |
| 269 | bad: |
| 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 | */ |
| 285 | static 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 | |
| 301 | retry: |
| 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 | |
| 335 | write_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); |
| 345 | out_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 | */ |
| 361 | static 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 | |
| 470 | out_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 | */ |
| 484 | static 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 | */ |
| 520 | static 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 | */ |
| 674 | static 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 | |
| 701 | bad: |
| 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 | */ |
| 718 | static 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 | */ |
| 783 | int 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 | |
| 858 | out_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 | */ |
| 868 | static 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 | } |