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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (c) International Business Machines Corp., 20064 *5 * Author: Artem Bityutskiy (Битюцкий Артём)6 */7 8/*9 * UBI attaching sub-system.10 *11 * This sub-system is responsible for attaching MTD devices and it also12 * implements flash media scanning.13 *14 * The attaching information is represented by a &struct ubi_attach_info'15 * object. Information about volumes is represented by &struct ubi_ainf_volume16 * objects which are kept in volume RB-tree with root at the @volumes field.17 * The RB-tree is indexed by the volume ID.18 *19 * Logical eraseblocks are represented by &struct ubi_ainf_peb objects. These20 * objects are kept in per-volume RB-trees with the root at the corresponding21 * &struct ubi_ainf_volume object. To put it differently, we keep an RB-tree of22 * per-volume objects and each of these objects is the root of RB-tree of23 * per-LEB objects.24 *25 * Corrupted physical eraseblocks are put to the @corr list, free physical26 * eraseblocks are put to the @free list and the physical eraseblock to be27 * erased are put to the @erase list.28 *29 * About corruptions30 * ~~~~~~~~~~~~~~~~~31 *32 * UBI protects EC and VID headers with CRC-32 checksums, so it can detect33 * whether the headers are corrupted or not. Sometimes UBI also protects the34 * data with CRC-32, e.g., when it executes the atomic LEB change operation, or35 * when it moves the contents of a PEB for wear-leveling purposes.36 *37 * UBI tries to distinguish between 2 types of corruptions.38 *39 * 1. Corruptions caused by power cuts. These are expected corruptions and UBI40 * tries to handle them gracefully, without printing too many warnings and41 * error messages. The idea is that we do not lose important data in these42 * cases - we may lose only the data which were being written to the media just43 * before the power cut happened, and the upper layers (e.g., UBIFS) are44 * supposed to handle such data losses (e.g., by using the FS journal).45 *46 * When UBI detects a corruption (CRC-32 mismatch) in a PEB, and it looks like47 * the reason is a power cut, UBI puts this PEB to the @erase list, and all48 * PEBs in the @erase list are scheduled for erasure later.49 *50 * 2. Unexpected corruptions which are not caused by power cuts. During51 * attaching, such PEBs are put to the @corr list and UBI preserves them.52 * Obviously, this lessens the amount of available PEBs, and if at some point53 * UBI runs out of free PEBs, it switches to R/O mode. UBI also loudly informs54 * about such PEBs every time the MTD device is attached.55 *56 * However, it is difficult to reliably distinguish between these types of57 * corruptions and UBI's strategy is as follows (in case of attaching by58 * scanning). UBI assumes corruption type 2 if the VID header is corrupted and59 * the data area does not contain all 0xFFs, and there were no bit-flips or60 * integrity errors (e.g., ECC errors in case of NAND) while reading the data61 * area. Otherwise UBI assumes corruption type 1. So the decision criteria62 * are as follows.63 * o If the data area contains only 0xFFs, there are no data, and it is safe64 * to just erase this PEB - this is corruption type 1.65 * o If the data area has bit-flips or data integrity errors (ECC errors on66 * NAND), it is probably a PEB which was being erased when power cut67 * happened, so this is corruption type 1. However, this is just a guess,68 * which might be wrong.69 * o Otherwise this is corruption type 2.70 */71 72#include <linux/err.h>73#include <linux/slab.h>74#include <linux/crc32.h>75#include <linux/math64.h>76#include <linux/random.h>77#include "ubi.h"78 79static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai);80 81#define AV_FIND BIT(0)82#define AV_ADD BIT(1)83#define AV_FIND_OR_ADD (AV_FIND | AV_ADD)84 85/**86 * find_or_add_av - internal function to find a volume, add a volume or do87 * both (find and add if missing).88 * @ai: attaching information89 * @vol_id: the requested volume ID90 * @flags: a combination of the %AV_FIND and %AV_ADD flags describing the91 * expected operation. If only %AV_ADD is set, -EEXIST is returned92 * if the volume already exists. If only %AV_FIND is set, NULL is93 * returned if the volume does not exist. And if both flags are94 * set, the helper first tries to find an existing volume, and if95 * it does not exist it creates a new one.96 * @created: in value used to inform the caller whether it"s a newly created97 * volume or not.98 *99 * This function returns a pointer to a volume description or an ERR_PTR if100 * the operation failed. It can also return NULL if only %AV_FIND is set and101 * the volume does not exist.102 */103static struct ubi_ainf_volume *find_or_add_av(struct ubi_attach_info *ai,104 int vol_id, unsigned int flags,105 bool *created)106{107 struct ubi_ainf_volume *av;108 struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;109 110 /* Walk the volume RB-tree to look if this volume is already present */111 while (*p) {112 parent = *p;113 av = rb_entry(parent, struct ubi_ainf_volume, rb);114 115 if (vol_id == av->vol_id) {116 *created = false;117 118 if (!(flags & AV_FIND))119 return ERR_PTR(-EEXIST);120 121 return av;122 }123 124 if (vol_id > av->vol_id)125 p = &(*p)->rb_left;126 else127 p = &(*p)->rb_right;128 }129 130 if (!(flags & AV_ADD))131 return NULL;132 133 /* The volume is absent - add it */134 av = kzalloc(sizeof(*av), GFP_KERNEL);135 if (!av)136 return ERR_PTR(-ENOMEM);137 138 av->vol_id = vol_id;139 140 if (vol_id > ai->highest_vol_id)141 ai->highest_vol_id = vol_id;142 143 rb_link_node(&av->rb, parent, p);144 rb_insert_color(&av->rb, &ai->volumes);145 ai->vols_found += 1;146 *created = true;147 dbg_bld("added volume %d", vol_id);148 return av;149}150 151/**152 * ubi_find_or_add_av - search for a volume in the attaching information and153 * add one if it does not exist.154 * @ai: attaching information155 * @vol_id: the requested volume ID156 * @created: whether the volume has been created or not157 *158 * This function returns a pointer to the new volume description or an159 * ERR_PTR if the operation failed.160 */161static struct ubi_ainf_volume *ubi_find_or_add_av(struct ubi_attach_info *ai,162 int vol_id, bool *created)163{164 return find_or_add_av(ai, vol_id, AV_FIND_OR_ADD, created);165}166 167/**168 * ubi_alloc_aeb - allocate an aeb element169 * @ai: attaching information170 * @pnum: physical eraseblock number171 * @ec: erase counter of the physical eraseblock172 *173 * Allocate an aeb object and initialize the pnum and ec information.174 * vol_id and lnum are set to UBI_UNKNOWN, and the other fields are175 * initialized to zero.176 * Note that the element is not added in any list or RB tree.177 */178struct ubi_ainf_peb *ubi_alloc_aeb(struct ubi_attach_info *ai, int pnum,179 int ec)180{181 struct ubi_ainf_peb *aeb;182 183 aeb = kmem_cache_zalloc(ai->aeb_slab_cache, GFP_KERNEL);184 if (!aeb)185 return NULL;186 187 aeb->pnum = pnum;188 aeb->ec = ec;189 aeb->vol_id = UBI_UNKNOWN;190 aeb->lnum = UBI_UNKNOWN;191 192 return aeb;193}194 195/**196 * ubi_free_aeb - free an aeb element197 * @ai: attaching information198 * @aeb: the element to free199 *200 * Free an aeb object. The caller must have removed the element from any list201 * or RB tree.202 */203void ubi_free_aeb(struct ubi_attach_info *ai, struct ubi_ainf_peb *aeb)204{205 kmem_cache_free(ai->aeb_slab_cache, aeb);206}207 208/**209 * add_to_list - add physical eraseblock to a list.210 * @ai: attaching information211 * @pnum: physical eraseblock number to add212 * @vol_id: the last used volume id for the PEB213 * @lnum: the last used LEB number for the PEB214 * @ec: erase counter of the physical eraseblock215 * @to_head: if not zero, add to the head of the list216 * @list: the list to add to217 *218 * This function allocates a 'struct ubi_ainf_peb' object for physical219 * eraseblock @pnum and adds it to the "free", "erase", or "alien" lists.220 * It stores the @lnum and @vol_id alongside, which can both be221 * %UBI_UNKNOWN if they are not available, not readable, or not assigned.222 * If @to_head is not zero, PEB will be added to the head of the list, which223 * basically means it will be processed first later. E.g., we add corrupted224 * PEBs (corrupted due to power cuts) to the head of the erase list to make225 * sure we erase them first and get rid of corruptions ASAP. This function226 * returns zero in case of success and a negative error code in case of227 * failure.228 */229static int add_to_list(struct ubi_attach_info *ai, int pnum, int vol_id,230 int lnum, int ec, int to_head, struct list_head *list)231{232 struct ubi_ainf_peb *aeb;233 234 if (list == &ai->free) {235 dbg_bld("add to free: PEB %d, EC %d", pnum, ec);236 } else if (list == &ai->erase) {237 dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);238 } else if (list == &ai->alien) {239 dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);240 ai->alien_peb_count += 1;241 } else242 BUG();243 244 aeb = ubi_alloc_aeb(ai, pnum, ec);245 if (!aeb)246 return -ENOMEM;247 248 aeb->vol_id = vol_id;249 aeb->lnum = lnum;250 if (to_head)251 list_add(&aeb->u.list, list);252 else253 list_add_tail(&aeb->u.list, list);254 return 0;255}256 257/**258 * add_corrupted - add a corrupted physical eraseblock.259 * @ai: attaching information260 * @pnum: physical eraseblock number to add261 * @ec: erase counter of the physical eraseblock262 *263 * This function allocates a 'struct ubi_ainf_peb' object for a corrupted264 * physical eraseblock @pnum and adds it to the 'corr' list. The corruption265 * was presumably not caused by a power cut. Returns zero in case of success266 * and a negative error code in case of failure.267 */268static int add_corrupted(struct ubi_attach_info *ai, int pnum, int ec)269{270 struct ubi_ainf_peb *aeb;271 272 dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);273 274 aeb = ubi_alloc_aeb(ai, pnum, ec);275 if (!aeb)276 return -ENOMEM;277 278 ai->corr_peb_count += 1;279 list_add(&aeb->u.list, &ai->corr);280 return 0;281}282 283/**284 * add_fastmap - add a Fastmap related physical eraseblock.285 * @ai: attaching information286 * @pnum: physical eraseblock number the VID header came from287 * @vid_hdr: the volume identifier header288 * @ec: erase counter of the physical eraseblock289 *290 * This function allocates a 'struct ubi_ainf_peb' object for a Fastamp291 * physical eraseblock @pnum and adds it to the 'fastmap' list.292 * Such blocks can be Fastmap super and data blocks from both the most293 * recent Fastmap we're attaching from or from old Fastmaps which will294 * be erased.295 */296static int add_fastmap(struct ubi_attach_info *ai, int pnum,297 struct ubi_vid_hdr *vid_hdr, int ec)298{299 struct ubi_ainf_peb *aeb;300 301 aeb = ubi_alloc_aeb(ai, pnum, ec);302 if (!aeb)303 return -ENOMEM;304 305 aeb->vol_id = be32_to_cpu(vid_hdr->vol_id);306 aeb->sqnum = be64_to_cpu(vid_hdr->sqnum);307 list_add(&aeb->u.list, &ai->fastmap);308 309 dbg_bld("add to fastmap list: PEB %d, vol_id %d, sqnum: %llu", pnum,310 aeb->vol_id, aeb->sqnum);311 312 return 0;313}314 315/**316 * validate_vid_hdr - check volume identifier header.317 * @ubi: UBI device description object318 * @vid_hdr: the volume identifier header to check319 * @av: information about the volume this logical eraseblock belongs to320 * @pnum: physical eraseblock number the VID header came from321 *322 * This function checks that data stored in @vid_hdr is consistent. Returns323 * non-zero if an inconsistency was found and zero if not.324 *325 * Note, UBI does sanity check of everything it reads from the flash media.326 * Most of the checks are done in the I/O sub-system. Here we check that the327 * information in the VID header is consistent to the information in other VID328 * headers of the same volume.329 */330static int validate_vid_hdr(const struct ubi_device *ubi,331 const struct ubi_vid_hdr *vid_hdr,332 const struct ubi_ainf_volume *av, int pnum)333{334 int vol_type = vid_hdr->vol_type;335 int vol_id = be32_to_cpu(vid_hdr->vol_id);336 int used_ebs = be32_to_cpu(vid_hdr->used_ebs);337 int data_pad = be32_to_cpu(vid_hdr->data_pad);338 339 if (av->leb_count != 0) {340 int av_vol_type;341 342 /*343 * This is not the first logical eraseblock belonging to this344 * volume. Ensure that the data in its VID header is consistent345 * to the data in previous logical eraseblock headers.346 */347 348 if (vol_id != av->vol_id) {349 ubi_err(ubi, "inconsistent vol_id");350 goto bad;351 }352 353 if (av->vol_type == UBI_STATIC_VOLUME)354 av_vol_type = UBI_VID_STATIC;355 else356 av_vol_type = UBI_VID_DYNAMIC;357 358 if (vol_type != av_vol_type) {359 ubi_err(ubi, "inconsistent vol_type");360 goto bad;361 }362 363 if (used_ebs != av->used_ebs) {364 ubi_err(ubi, "inconsistent used_ebs");365 goto bad;366 }367 368 if (data_pad != av->data_pad) {369 ubi_err(ubi, "inconsistent data_pad");370 goto bad;371 }372 }373 374 return 0;375 376bad:377 ubi_err(ubi, "inconsistent VID header at PEB %d", pnum);378 ubi_dump_vid_hdr(vid_hdr);379 ubi_dump_av(av);380 return -EINVAL;381}382 383/**384 * add_volume - add volume to the attaching information.385 * @ai: attaching information386 * @vol_id: ID of the volume to add387 * @pnum: physical eraseblock number388 * @vid_hdr: volume identifier header389 *390 * If the volume corresponding to the @vid_hdr logical eraseblock is already391 * present in the attaching information, this function does nothing. Otherwise392 * it adds corresponding volume to the attaching information. Returns a pointer393 * to the allocated "av" object in case of success and a negative error code in394 * case of failure.395 */396static struct ubi_ainf_volume *add_volume(struct ubi_attach_info *ai,397 int vol_id, int pnum,398 const struct ubi_vid_hdr *vid_hdr)399{400 struct ubi_ainf_volume *av;401 bool created;402 403 ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));404 405 av = ubi_find_or_add_av(ai, vol_id, &created);406 if (IS_ERR(av) || !created)407 return av;408 409 av->used_ebs = be32_to_cpu(vid_hdr->used_ebs);410 av->data_pad = be32_to_cpu(vid_hdr->data_pad);411 av->compat = vid_hdr->compat;412 av->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME413 : UBI_STATIC_VOLUME;414 415 return av;416}417 418/**419 * ubi_compare_lebs - find out which logical eraseblock is newer.420 * @ubi: UBI device description object421 * @aeb: first logical eraseblock to compare422 * @pnum: physical eraseblock number of the second logical eraseblock to423 * compare424 * @vid_hdr: volume identifier header of the second logical eraseblock425 *426 * This function compares 2 copies of a LEB and informs which one is newer. In427 * case of success this function returns a positive value, in case of failure, a428 * negative error code is returned. The success return codes use the following429 * bits:430 * o bit 0 is cleared: the first PEB (described by @aeb) is newer than the431 * second PEB (described by @pnum and @vid_hdr);432 * o bit 0 is set: the second PEB is newer;433 * o bit 1 is cleared: no bit-flips were detected in the newer LEB;434 * o bit 1 is set: bit-flips were detected in the newer LEB;435 * o bit 2 is cleared: the older LEB is not corrupted;436 * o bit 2 is set: the older LEB is corrupted.437 */438int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,439 int pnum, const struct ubi_vid_hdr *vid_hdr)440{441 int len, err, second_is_newer, bitflips = 0, corrupted = 0;442 uint32_t data_crc, crc;443 struct ubi_vid_io_buf *vidb = NULL;444 unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);445 446 if (sqnum2 == aeb->sqnum) {447 /*448 * This must be a really ancient UBI image which has been449 * created before sequence numbers support has been added. At450 * that times we used 32-bit LEB versions stored in logical451 * eraseblocks. That was before UBI got into mainline. We do not452 * support these images anymore. Well, those images still work,453 * but only if no unclean reboots happened.454 */455 ubi_err(ubi, "unsupported on-flash UBI format");456 return -EINVAL;457 }458 459 /* Obviously the LEB with lower sequence counter is older */460 second_is_newer = (sqnum2 > aeb->sqnum);461 462 /*463 * Now we know which copy is newer. If the copy flag of the PEB with464 * newer version is not set, then we just return, otherwise we have to465 * check data CRC. For the second PEB we already have the VID header,466 * for the first one - we'll need to re-read it from flash.467 *468 * Note: this may be optimized so that we wouldn't read twice.469 */470 471 if (second_is_newer) {472 if (!vid_hdr->copy_flag) {473 /* It is not a copy, so it is newer */474 dbg_bld("second PEB %d is newer, copy_flag is unset",475 pnum);476 return 1;477 }478 } else {479 if (!aeb->copy_flag) {480 /* It is not a copy, so it is newer */481 dbg_bld("first PEB %d is newer, copy_flag is unset",482 pnum);483 return bitflips << 1;484 }485 486 vidb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);487 if (!vidb)488 return -ENOMEM;489 490 pnum = aeb->pnum;491 err = ubi_io_read_vid_hdr(ubi, pnum, vidb, 0);492 if (err) {493 if (err == UBI_IO_BITFLIPS)494 bitflips = 1;495 else {496 ubi_err(ubi, "VID of PEB %d header is bad, but it was OK earlier, err %d",497 pnum, err);498 if (err > 0)499 err = -EIO;500 501 goto out_free_vidh;502 }503 }504 505 vid_hdr = ubi_get_vid_hdr(vidb);506 }507 508 /* Read the data of the copy and check the CRC */509 510 len = be32_to_cpu(vid_hdr->data_size);511 512 mutex_lock(&ubi->buf_mutex);513 err = ubi_io_read_data(ubi, ubi->peb_buf, pnum, 0, len);514 if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))515 goto out_unlock;516 517 data_crc = be32_to_cpu(vid_hdr->data_crc);518 crc = crc32(UBI_CRC32_INIT, ubi->peb_buf, len);519 if (crc != data_crc) {520 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",521 pnum, crc, data_crc);522 corrupted = 1;523 bitflips = 0;524 second_is_newer = !second_is_newer;525 } else {526 dbg_bld("PEB %d CRC is OK", pnum);527 bitflips |= !!err;528 }529 mutex_unlock(&ubi->buf_mutex);530 531 ubi_free_vid_buf(vidb);532 533 if (second_is_newer)534 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);535 else536 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);537 538 return second_is_newer | (bitflips << 1) | (corrupted << 2);539 540out_unlock:541 mutex_unlock(&ubi->buf_mutex);542out_free_vidh:543 ubi_free_vid_buf(vidb);544 return err;545}546 547/**548 * ubi_add_to_av - add used physical eraseblock to the attaching information.549 * @ubi: UBI device description object550 * @ai: attaching information551 * @pnum: the physical eraseblock number552 * @ec: erase counter553 * @vid_hdr: the volume identifier header554 * @bitflips: if bit-flips were detected when this physical eraseblock was read555 *556 * This function adds information about a used physical eraseblock to the557 * 'used' tree of the corresponding volume. The function is rather complex558 * because it has to handle cases when this is not the first physical559 * eraseblock belonging to the same logical eraseblock, and the newer one has560 * to be picked, while the older one has to be dropped. This function returns561 * zero in case of success and a negative error code in case of failure.562 */563int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,564 int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips)565{566 int err, vol_id, lnum;567 unsigned long long sqnum;568 struct ubi_ainf_volume *av;569 struct ubi_ainf_peb *aeb;570 struct rb_node **p, *parent = NULL;571 572 vol_id = be32_to_cpu(vid_hdr->vol_id);573 lnum = be32_to_cpu(vid_hdr->lnum);574 sqnum = be64_to_cpu(vid_hdr->sqnum);575 576 dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",577 pnum, vol_id, lnum, ec, sqnum, bitflips);578 579 av = add_volume(ai, vol_id, pnum, vid_hdr);580 if (IS_ERR(av))581 return PTR_ERR(av);582 583 if (ai->max_sqnum < sqnum)584 ai->max_sqnum = sqnum;585 586 /*587 * Walk the RB-tree of logical eraseblocks of volume @vol_id to look588 * if this is the first instance of this logical eraseblock or not.589 */590 p = &av->root.rb_node;591 while (*p) {592 int cmp_res;593 594 parent = *p;595 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);596 if (lnum != aeb->lnum) {597 if (lnum < aeb->lnum)598 p = &(*p)->rb_left;599 else600 p = &(*p)->rb_right;601 continue;602 }603 604 /*605 * There is already a physical eraseblock describing the same606 * logical eraseblock present.607 */608 609 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, EC %d",610 aeb->pnum, aeb->sqnum, aeb->ec);611 612 /*613 * Make sure that the logical eraseblocks have different614 * sequence numbers. Otherwise the image is bad.615 *616 * However, if the sequence number is zero, we assume it must617 * be an ancient UBI image from the era when UBI did not have618 * sequence numbers. We still can attach these images, unless619 * there is a need to distinguish between old and new620 * eraseblocks, in which case we'll refuse the image in621 * 'ubi_compare_lebs()'. In other words, we attach old clean622 * images, but refuse attaching old images with duplicated623 * logical eraseblocks because there was an unclean reboot.624 */625 if (aeb->sqnum == sqnum && sqnum != 0) {626 ubi_err(ubi, "two LEBs with same sequence number %llu",627 sqnum);628 ubi_dump_aeb(aeb, 0);629 ubi_dump_vid_hdr(vid_hdr);630 return -EINVAL;631 }632 633 /*634 * Now we have to drop the older one and preserve the newer635 * one.636 */637 cmp_res = ubi_compare_lebs(ubi, aeb, pnum, vid_hdr);638 if (cmp_res < 0)639 return cmp_res;640 641 if (cmp_res & 1) {642 /*643 * This logical eraseblock is newer than the one644 * found earlier.645 */646 err = validate_vid_hdr(ubi, vid_hdr, av, pnum);647 if (err)648 return err;649 650 err = add_to_list(ai, aeb->pnum, aeb->vol_id,651 aeb->lnum, aeb->ec, cmp_res & 4,652 &ai->erase);653 if (err)654 return err;655 656 aeb->ec = ec;657 aeb->pnum = pnum;658 aeb->vol_id = vol_id;659 aeb->lnum = lnum;660 aeb->scrub = ((cmp_res & 2) || bitflips);661 aeb->copy_flag = vid_hdr->copy_flag;662 aeb->sqnum = sqnum;663 664 if (av->highest_lnum == lnum)665 av->last_data_size =666 be32_to_cpu(vid_hdr->data_size);667 668 return 0;669 } else {670 /*671 * This logical eraseblock is older than the one found672 * previously.673 */674 return add_to_list(ai, pnum, vol_id, lnum, ec,675 cmp_res & 4, &ai->erase);676 }677 }678 679 /*680 * We've met this logical eraseblock for the first time, add it to the681 * attaching information.682 */683 684 err = validate_vid_hdr(ubi, vid_hdr, av, pnum);685 if (err)686 return err;687 688 aeb = ubi_alloc_aeb(ai, pnum, ec);689 if (!aeb)690 return -ENOMEM;691 692 aeb->vol_id = vol_id;693 aeb->lnum = lnum;694 aeb->scrub = bitflips;695 aeb->copy_flag = vid_hdr->copy_flag;696 aeb->sqnum = sqnum;697 698 if (av->highest_lnum <= lnum) {699 av->highest_lnum = lnum;700 av->last_data_size = be32_to_cpu(vid_hdr->data_size);701 }702 703 av->leb_count += 1;704 rb_link_node(&aeb->u.rb, parent, p);705 rb_insert_color(&aeb->u.rb, &av->root);706 return 0;707}708 709/**710 * ubi_add_av - add volume to the attaching information.711 * @ai: attaching information712 * @vol_id: the requested volume ID713 *714 * This function returns a pointer to the new volume description or an715 * ERR_PTR if the operation failed.716 */717struct ubi_ainf_volume *ubi_add_av(struct ubi_attach_info *ai, int vol_id)718{719 bool created;720 721 return find_or_add_av(ai, vol_id, AV_ADD, &created);722}723 724/**725 * ubi_find_av - find volume in the attaching information.726 * @ai: attaching information727 * @vol_id: the requested volume ID728 *729 * This function returns a pointer to the volume description or %NULL if there730 * are no data about this volume in the attaching information.731 */732struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,733 int vol_id)734{735 bool created;736 737 return find_or_add_av((struct ubi_attach_info *)ai, vol_id, AV_FIND,738 &created);739}740 741static void destroy_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av,742 struct list_head *list);743 744/**745 * ubi_remove_av - delete attaching information about a volume.746 * @ai: attaching information747 * @av: the volume attaching information to delete748 */749void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av)750{751 dbg_bld("remove attaching information about volume %d", av->vol_id);752 753 rb_erase(&av->rb, &ai->volumes);754 destroy_av(ai, av, &ai->erase);755 ai->vols_found -= 1;756}757 758/**759 * early_erase_peb - erase a physical eraseblock.760 * @ubi: UBI device description object761 * @ai: attaching information762 * @pnum: physical eraseblock number to erase;763 * @ec: erase counter value to write (%UBI_UNKNOWN if it is unknown)764 *765 * This function erases physical eraseblock 'pnum', and writes the erase766 * counter header to it. This function should only be used on UBI device767 * initialization stages, when the EBA sub-system had not been yet initialized.768 * This function returns zero in case of success and a negative error code in769 * case of failure.770 */771static int early_erase_peb(struct ubi_device *ubi,772 const struct ubi_attach_info *ai, int pnum, int ec)773{774 int err;775 struct ubi_ec_hdr *ec_hdr;776 777 if ((long long)ec >= UBI_MAX_ERASECOUNTER) {778 /*779 * Erase counter overflow. Upgrade UBI and use 64-bit780 * erase counters internally.781 */782 ubi_err(ubi, "erase counter overflow at PEB %d, EC %d",783 pnum, ec);784 return -EINVAL;785 }786 787 ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);788 if (!ec_hdr)789 return -ENOMEM;790 791 ec_hdr->ec = cpu_to_be64(ec);792 793 err = ubi_io_sync_erase(ubi, pnum, 0);794 if (err < 0)795 goto out_free;796 797 err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);798 799out_free:800 kfree(ec_hdr);801 return err;802}803 804/**805 * ubi_early_get_peb - get a free physical eraseblock.806 * @ubi: UBI device description object807 * @ai: attaching information808 *809 * This function returns a free physical eraseblock. It is supposed to be810 * called on the UBI initialization stages when the wear-leveling sub-system is811 * not initialized yet. This function picks a physical eraseblocks from one of812 * the lists, writes the EC header if it is needed, and removes it from the813 * list.814 *815 * This function returns a pointer to the "aeb" of the found free PEB in case816 * of success and an error code in case of failure.817 */818struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,819 struct ubi_attach_info *ai)820{821 int err = 0;822 struct ubi_ainf_peb *aeb, *tmp_aeb;823 824 if (!list_empty(&ai->free)) {825 aeb = list_entry(ai->free.next, struct ubi_ainf_peb, u.list);826 list_del(&aeb->u.list);827 dbg_bld("return free PEB %d, EC %d", aeb->pnum, aeb->ec);828 return aeb;829 }830 831 /*832 * We try to erase the first physical eraseblock from the erase list833 * and pick it if we succeed, or try to erase the next one if not. And834 * so forth. We don't want to take care about bad eraseblocks here -835 * they'll be handled later.836 */837 list_for_each_entry_safe(aeb, tmp_aeb, &ai->erase, u.list) {838 if (aeb->ec == UBI_UNKNOWN)839 aeb->ec = ai->mean_ec;840 841 err = early_erase_peb(ubi, ai, aeb->pnum, aeb->ec+1);842 if (err)843 continue;844 845 aeb->ec += 1;846 list_del(&aeb->u.list);847 dbg_bld("return PEB %d, EC %d", aeb->pnum, aeb->ec);848 return aeb;849 }850 851 ubi_err(ubi, "no free eraseblocks");852 return ERR_PTR(-ENOSPC);853}854 855/**856 * check_corruption - check the data area of PEB.857 * @ubi: UBI device description object858 * @vid_hdr: the (corrupted) VID header of this PEB859 * @pnum: the physical eraseblock number to check860 *861 * This is a helper function which is used to distinguish between VID header862 * corruptions caused by power cuts and other reasons. If the PEB contains only863 * 0xFF bytes in the data area, the VID header is most probably corrupted864 * because of a power cut (%0 is returned in this case). Otherwise, it was865 * probably corrupted for some other reasons (%1 is returned in this case). A866 * negative error code is returned if a read error occurred.867 *868 * If the corruption reason was a power cut, UBI can safely erase this PEB.869 * Otherwise, it should preserve it to avoid possibly destroying important870 * information.871 */872static int check_corruption(struct ubi_device *ubi, struct ubi_vid_hdr *vid_hdr,873 int pnum)874{875 int err;876 877 mutex_lock(&ubi->buf_mutex);878 memset(ubi->peb_buf, 0x00, ubi->leb_size);879 880 err = ubi_io_read(ubi, ubi->peb_buf, pnum, ubi->leb_start,881 ubi->leb_size);882 if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) {883 /*884 * Bit-flips or integrity errors while reading the data area.885 * It is difficult to say for sure what type of corruption is886 * this, but presumably a power cut happened while this PEB was887 * erased, so it became unstable and corrupted, and should be888 * erased.889 */890 err = 0;891 goto out_unlock;892 }893 894 if (err)895 goto out_unlock;896 897 if (ubi_check_pattern(ubi->peb_buf, 0xFF, ubi->leb_size))898 goto out_unlock;899 900 ubi_err(ubi, "PEB %d contains corrupted VID header, and the data does not contain all 0xFF",901 pnum);902 ubi_err(ubi, "this may be a non-UBI PEB or a severe VID header corruption which requires manual inspection");903 ubi_dump_vid_hdr(vid_hdr);904 pr_err("hexdump of PEB %d offset %d, length %d",905 pnum, ubi->leb_start, ubi->leb_size);906 ubi_dbg_print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,907 ubi->peb_buf, ubi->leb_size, 1);908 err = 1;909 910out_unlock:911 mutex_unlock(&ubi->buf_mutex);912 return err;913}914 915static bool vol_ignored(int vol_id)916{917 switch (vol_id) {918 case UBI_LAYOUT_VOLUME_ID:919 return true;920 }921 922#ifdef CONFIG_MTD_UBI_FASTMAP923 return ubi_is_fm_vol(vol_id);924#else925 return false;926#endif927}928 929/**930 * scan_peb - scan and process UBI headers of a PEB.931 * @ubi: UBI device description object932 * @ai: attaching information933 * @pnum: the physical eraseblock number934 * @fast: true if we're scanning for a Fastmap935 *936 * This function reads UBI headers of PEB @pnum, checks them, and adds937 * information about this PEB to the corresponding list or RB-tree in the938 * "attaching info" structure. Returns zero if the physical eraseblock was939 * successfully handled and a negative error code in case of failure.940 */941static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,942 int pnum, bool fast)943{944 struct ubi_ec_hdr *ech = ai->ech;945 struct ubi_vid_io_buf *vidb = ai->vidb;946 struct ubi_vid_hdr *vidh = ubi_get_vid_hdr(vidb);947 long long ec;948 int err, bitflips = 0, vol_id = -1, ec_err = 0;949 950 dbg_bld("scan PEB %d", pnum);951 952 /* Skip bad physical eraseblocks */953 err = ubi_io_is_bad(ubi, pnum);954 if (err < 0)955 return err;956 else if (err) {957 ai->bad_peb_count += 1;958 return 0;959 }960 961 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);962 if (err < 0)963 return err;964 switch (err) {965 case 0:966 break;967 case UBI_IO_BITFLIPS:968 bitflips = 1;969 break;970 case UBI_IO_FF:971 ai->empty_peb_count += 1;972 return add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN,973 UBI_UNKNOWN, 0, &ai->erase);974 case UBI_IO_FF_BITFLIPS:975 ai->empty_peb_count += 1;976 return add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN,977 UBI_UNKNOWN, 1, &ai->erase);978 case UBI_IO_BAD_HDR_EBADMSG:979 case UBI_IO_BAD_HDR:980 /*981 * We have to also look at the VID header, possibly it is not982 * corrupted. Set %bitflips flag in order to make this PEB be983 * moved and EC be re-created.984 */985 ec_err = err;986 ec = UBI_UNKNOWN;987 bitflips = 1;988 break;989 default:990 ubi_err(ubi, "'ubi_io_read_ec_hdr()' returned unknown code %d",991 err);992 return -EINVAL;993 }994 995 if (!ec_err) {996 int image_seq;997 998 /* Make sure UBI version is OK */999 if (ech->version != UBI_VERSION) {1000 ubi_err(ubi, "this UBI version is %d, image version is %d",1001 UBI_VERSION, (int)ech->version);1002 return -EINVAL;1003 }1004 1005 ec = be64_to_cpu(ech->ec);1006 if (ec > UBI_MAX_ERASECOUNTER) {1007 /*1008 * Erase counter overflow. The EC headers have 64 bits1009 * reserved, but we anyway make use of only 31 bit1010 * values, as this seems to be enough for any existing1011 * flash. Upgrade UBI and use 64-bit erase counters1012 * internally.1013 */1014 ubi_err(ubi, "erase counter overflow, max is %d",1015 UBI_MAX_ERASECOUNTER);1016 ubi_dump_ec_hdr(ech);1017 return -EINVAL;1018 }1019 1020 /*1021 * Make sure that all PEBs have the same image sequence number.1022 * This allows us to detect situations when users flash UBI1023 * images incorrectly, so that the flash has the new UBI image1024 * and leftovers from the old one. This feature was added1025 * relatively recently, and the sequence number was always1026 * zero, because old UBI implementations always set it to zero.1027 * For this reasons, we do not panic if some PEBs have zero1028 * sequence number, while other PEBs have non-zero sequence1029 * number.1030 */1031 image_seq = be32_to_cpu(ech->image_seq);1032 if (!ubi->image_seq)1033 ubi->image_seq = image_seq;1034 if (image_seq && ubi->image_seq != image_seq) {1035 ubi_err(ubi, "bad image sequence number %d in PEB %d, expected %d",1036 image_seq, pnum, ubi->image_seq);1037 ubi_dump_ec_hdr(ech);1038 return -EINVAL;1039 }1040 }1041 1042 /* OK, we've done with the EC header, let's look at the VID header */1043 1044 err = ubi_io_read_vid_hdr(ubi, pnum, vidb, 0);1045 if (err < 0)1046 return err;1047 switch (err) {1048 case 0:1049 break;1050 case UBI_IO_BITFLIPS:1051 bitflips = 1;1052 break;1053 case UBI_IO_BAD_HDR_EBADMSG:1054 if (ec_err == UBI_IO_BAD_HDR_EBADMSG)1055 /*1056 * Both EC and VID headers are corrupted and were read1057 * with data integrity error, probably this is a bad1058 * PEB, bit it is not marked as bad yet. This may also1059 * be a result of power cut during erasure.1060 */1061 ai->maybe_bad_peb_count += 1;1062 fallthrough;1063 case UBI_IO_BAD_HDR:1064 /*1065 * If we're facing a bad VID header we have to drop *all*1066 * Fastmap data structures we find. The most recent Fastmap1067 * could be bad and therefore there is a chance that we attach1068 * from an old one. On a fine MTD stack a PEB must not render1069 * bad all of a sudden, but the reality is different.1070 * So, let's be paranoid and help finding the root cause by1071 * falling back to scanning mode instead of attaching with a1072 * bad EBA table and cause data corruption which is hard to1073 * analyze.1074 */1075 if (fast)1076 ai->force_full_scan = 1;1077 1078 if (ec_err)1079 /*1080 * Both headers are corrupted. There is a possibility1081 * that this a valid UBI PEB which has corresponding1082 * LEB, but the headers are corrupted. However, it is1083 * impossible to distinguish it from a PEB which just1084 * contains garbage because of a power cut during erase1085 * operation. So we just schedule this PEB for erasure.1086 *1087 * Besides, in case of NOR flash, we deliberately1088 * corrupt both headers because NOR flash erasure is1089 * slow and can start from the end.1090 */1091 err = 0;1092 else1093 /*1094 * The EC was OK, but the VID header is corrupted. We1095 * have to check what is in the data area.1096 */1097 err = check_corruption(ubi, vidh, pnum);1098 1099 if (err < 0)1100 return err;1101 else if (!err)1102 /* This corruption is caused by a power cut */1103 err = add_to_list(ai, pnum, UBI_UNKNOWN,1104 UBI_UNKNOWN, ec, 1, &ai->erase);1105 else1106 /* This is an unexpected corruption */1107 err = add_corrupted(ai, pnum, ec);1108 if (err)1109 return err;1110 goto adjust_mean_ec;1111 case UBI_IO_FF_BITFLIPS:1112 err = add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN,1113 ec, 1, &ai->erase);1114 if (err)1115 return err;1116 goto adjust_mean_ec;1117 case UBI_IO_FF:1118 if (ec_err || bitflips)1119 err = add_to_list(ai, pnum, UBI_UNKNOWN,1120 UBI_UNKNOWN, ec, 1, &ai->erase);1121 else1122 err = add_to_list(ai, pnum, UBI_UNKNOWN,1123 UBI_UNKNOWN, ec, 0, &ai->free);1124 if (err)1125 return err;1126 goto adjust_mean_ec;1127 default:1128 ubi_err(ubi, "'ubi_io_read_vid_hdr()' returned unknown code %d",1129 err);1130 return -EINVAL;1131 }1132 1133 vol_id = be32_to_cpu(vidh->vol_id);1134 if (vol_id > UBI_MAX_VOLUMES && !vol_ignored(vol_id)) {1135 int lnum = be32_to_cpu(vidh->lnum);1136 1137 /* Unsupported internal volume */1138 switch (vidh->compat) {1139 case UBI_COMPAT_DELETE:1140 ubi_msg(ubi, "\"delete\" compatible internal volume %d:%d found, will remove it",1141 vol_id, lnum);1142 1143 err = add_to_list(ai, pnum, vol_id, lnum,1144 ec, 1, &ai->erase);1145 if (err)1146 return err;1147 return 0;1148 1149 case UBI_COMPAT_RO:1150 ubi_msg(ubi, "read-only compatible internal volume %d:%d found, switch to read-only mode",1151 vol_id, lnum);1152 ubi->ro_mode = 1;1153 break;1154 1155 case UBI_COMPAT_PRESERVE:1156 ubi_msg(ubi, "\"preserve\" compatible internal volume %d:%d found",1157 vol_id, lnum);1158 err = add_to_list(ai, pnum, vol_id, lnum,1159 ec, 0, &ai->alien);1160 if (err)1161 return err;1162 return 0;1163 1164 case UBI_COMPAT_REJECT:1165 ubi_err(ubi, "incompatible internal volume %d:%d found",1166 vol_id, lnum);1167 return -EINVAL;1168 }1169 }1170 1171 if (ec_err)1172 ubi_warn(ubi, "valid VID header but corrupted EC header at PEB %d",1173 pnum);1174 1175 if (ubi_is_fm_vol(vol_id))1176 err = add_fastmap(ai, pnum, vidh, ec);1177 else1178 err = ubi_add_to_av(ubi, ai, pnum, ec, vidh, bitflips);1179 1180 if (err)1181 return err;1182 1183adjust_mean_ec:1184 if (!ec_err) {1185 ai->ec_sum += ec;1186 ai->ec_count += 1;1187 if (ec > ai->max_ec)1188 ai->max_ec = ec;1189 if (ec < ai->min_ec)1190 ai->min_ec = ec;1191 }1192 1193 return 0;1194}1195 1196/**1197 * late_analysis - analyze the overall situation with PEB.1198 * @ubi: UBI device description object1199 * @ai: attaching information1200 *1201 * This is a helper function which takes a look what PEBs we have after we1202 * gather information about all of them ("ai" is compete). It decides whether1203 * the flash is empty and should be formatted of whether there are too many1204 * corrupted PEBs and we should not attach this MTD device. Returns zero if we1205 * should proceed with attaching the MTD device, and %-EINVAL if we should not.1206 */1207static int late_analysis(struct ubi_device *ubi, struct ubi_attach_info *ai)1208{1209 struct ubi_ainf_peb *aeb;1210 int max_corr, peb_count;1211 1212 peb_count = ubi->peb_count - ai->bad_peb_count - ai->alien_peb_count;1213 max_corr = peb_count / 20 ?: 8;1214 1215 /*1216 * Few corrupted PEBs is not a problem and may be just a result of1217 * unclean reboots. However, many of them may indicate some problems1218 * with the flash HW or driver.1219 */1220 if (ai->corr_peb_count) {1221 ubi_err(ubi, "%d PEBs are corrupted and preserved",1222 ai->corr_peb_count);1223 pr_err("Corrupted PEBs are:");1224 list_for_each_entry(aeb, &ai->corr, u.list)1225 pr_cont(" %d", aeb->pnum);1226 pr_cont("\n");1227 1228 /*1229 * If too many PEBs are corrupted, we refuse attaching,1230 * otherwise, only print a warning.1231 */1232 if (ai->corr_peb_count >= max_corr) {1233 ubi_err(ubi, "too many corrupted PEBs, refusing");1234 return -EINVAL;1235 }1236 }1237 1238 if (ai->empty_peb_count + ai->maybe_bad_peb_count == peb_count) {1239 /*1240 * All PEBs are empty, or almost all - a couple PEBs look like1241 * they may be bad PEBs which were not marked as bad yet.1242 *1243 * This piece of code basically tries to distinguish between1244 * the following situations:1245 *1246 * 1. Flash is empty, but there are few bad PEBs, which are not1247 * marked as bad so far, and which were read with error. We1248 * want to go ahead and format this flash. While formatting,1249 * the faulty PEBs will probably be marked as bad.1250 *1251 * 2. Flash contains non-UBI data and we do not want to format1252 * it and destroy possibly important information.1253 */1254 if (ai->maybe_bad_peb_count <= 2) {1255 ai->is_empty = 1;1256 ubi_msg(ubi, "empty MTD device detected");1257 get_random_bytes(&ubi->image_seq,1258 sizeof(ubi->image_seq));1259 } else {1260 ubi_err(ubi, "MTD device is not UBI-formatted and possibly contains non-UBI data - refusing it");1261 return -EINVAL;1262 }1263 1264 }1265 1266 return 0;1267}1268 1269/**1270 * destroy_av - free volume attaching information.1271 * @av: volume attaching information1272 * @ai: attaching information1273 * @list: put the aeb elements in there if !NULL, otherwise free them1274 *1275 * This function destroys the volume attaching information.1276 */1277static void destroy_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av,1278 struct list_head *list)1279{1280 struct ubi_ainf_peb *aeb;1281 struct rb_node *this = av->root.rb_node;1282 1283 while (this) {1284 if (this->rb_left)1285 this = this->rb_left;1286 else if (this->rb_right)1287 this = this->rb_right;1288 else {1289 aeb = rb_entry(this, struct ubi_ainf_peb, u.rb);1290 this = rb_parent(this);1291 if (this) {1292 if (this->rb_left == &aeb->u.rb)1293 this->rb_left = NULL;1294 else1295 this->rb_right = NULL;1296 }1297 1298 if (list)1299 list_add_tail(&aeb->u.list, list);1300 else1301 ubi_free_aeb(ai, aeb);1302 }1303 }1304 kfree(av);1305}1306 1307/**1308 * destroy_ai - destroy attaching information.1309 * @ai: attaching information1310 */1311static void destroy_ai(struct ubi_attach_info *ai)1312{1313 struct ubi_ainf_peb *aeb, *aeb_tmp;1314 struct ubi_ainf_volume *av;1315 struct rb_node *rb;1316 1317 list_for_each_entry_safe(aeb, aeb_tmp, &ai->alien, u.list) {1318 list_del(&aeb->u.list);1319 ubi_free_aeb(ai, aeb);1320 }1321 list_for_each_entry_safe(aeb, aeb_tmp, &ai->erase, u.list) {1322 list_del(&aeb->u.list);1323 ubi_free_aeb(ai, aeb);1324 }1325 list_for_each_entry_safe(aeb, aeb_tmp, &ai->corr, u.list) {1326 list_del(&aeb->u.list);1327 ubi_free_aeb(ai, aeb);1328 }1329 list_for_each_entry_safe(aeb, aeb_tmp, &ai->free, u.list) {1330 list_del(&aeb->u.list);1331 ubi_free_aeb(ai, aeb);1332 }1333 list_for_each_entry_safe(aeb, aeb_tmp, &ai->fastmap, u.list) {1334 list_del(&aeb->u.list);1335 ubi_free_aeb(ai, aeb);1336 }1337 1338 /* Destroy the volume RB-tree */1339 rb = ai->volumes.rb_node;1340 while (rb) {1341 if (rb->rb_left)1342 rb = rb->rb_left;1343 else if (rb->rb_right)1344 rb = rb->rb_right;1345 else {1346 av = rb_entry(rb, struct ubi_ainf_volume, rb);1347 1348 rb = rb_parent(rb);1349 if (rb) {1350 if (rb->rb_left == &av->rb)1351 rb->rb_left = NULL;1352 else1353 rb->rb_right = NULL;1354 }1355 1356 destroy_av(ai, av, NULL);1357 }1358 }1359 1360 kmem_cache_destroy(ai->aeb_slab_cache);1361 kfree(ai);1362}1363 1364/**1365 * scan_all - scan entire MTD device.1366 * @ubi: UBI device description object1367 * @ai: attach info object1368 * @start: start scanning at this PEB1369 *1370 * This function does full scanning of an MTD device and returns complete1371 * information about it in form of a "struct ubi_attach_info" object. In case1372 * of failure, an error code is returned.1373 */1374static int scan_all(struct ubi_device *ubi, struct ubi_attach_info *ai,1375 int start)1376{1377 int err, pnum;1378 struct rb_node *rb1, *rb2;1379 struct ubi_ainf_volume *av;1380 struct ubi_ainf_peb *aeb;1381 1382 err = -ENOMEM;1383 1384 ai->ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);1385 if (!ai->ech)1386 return err;1387 1388 ai->vidb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);1389 if (!ai->vidb)1390 goto out_ech;1391 1392 for (pnum = start; pnum < ubi->peb_count; pnum++) {1393 cond_resched();1394 1395 dbg_gen("process PEB %d", pnum);1396 err = scan_peb(ubi, ai, pnum, false);1397 if (err < 0)1398 goto out_vidh;1399 }1400 1401 ubi_msg(ubi, "scanning is finished");1402 1403 /* Calculate mean erase counter */1404 if (ai->ec_count)1405 ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);1406 1407 err = late_analysis(ubi, ai);1408 if (err)1409 goto out_vidh;1410 1411 /*1412 * In case of unknown erase counter we use the mean erase counter1413 * value.1414 */1415 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {1416 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)1417 if (aeb->ec == UBI_UNKNOWN)1418 aeb->ec = ai->mean_ec;1419 }1420 1421 list_for_each_entry(aeb, &ai->free, u.list) {1422 if (aeb->ec == UBI_UNKNOWN)1423 aeb->ec = ai->mean_ec;1424 }1425 1426 list_for_each_entry(aeb, &ai->corr, u.list)1427 if (aeb->ec == UBI_UNKNOWN)1428 aeb->ec = ai->mean_ec;1429 1430 list_for_each_entry(aeb, &ai->erase, u.list)1431 if (aeb->ec == UBI_UNKNOWN)1432 aeb->ec = ai->mean_ec;1433 1434 err = self_check_ai(ubi, ai);1435 if (err)1436 goto out_vidh;1437 1438 ubi_free_vid_buf(ai->vidb);1439 kfree(ai->ech);1440 1441 return 0;1442 1443out_vidh:1444 ubi_free_vid_buf(ai->vidb);1445out_ech:1446 kfree(ai->ech);1447 return err;1448}1449 1450static struct ubi_attach_info *alloc_ai(void)1451{1452 struct ubi_attach_info *ai;1453 1454 ai = kzalloc(sizeof(struct ubi_attach_info), GFP_KERNEL);1455 if (!ai)1456 return ai;1457 1458 INIT_LIST_HEAD(&ai->corr);1459 INIT_LIST_HEAD(&ai->free);1460 INIT_LIST_HEAD(&ai->erase);1461 INIT_LIST_HEAD(&ai->alien);1462 INIT_LIST_HEAD(&ai->fastmap);1463 ai->volumes = RB_ROOT;1464 ai->aeb_slab_cache = kmem_cache_create("ubi_aeb_slab_cache",1465 sizeof(struct ubi_ainf_peb),1466 0, 0, NULL);1467 if (!ai->aeb_slab_cache) {1468 kfree(ai);1469 ai = NULL;1470 }1471 1472 return ai;1473}1474 1475#ifdef CONFIG_MTD_UBI_FASTMAP1476 1477/**1478 * scan_fast - try to find a fastmap and attach from it.1479 * @ubi: UBI device description object1480 * @ai: attach info object1481 *1482 * Returns 0 on success, negative return values indicate an internal1483 * error.1484 * UBI_NO_FASTMAP denotes that no fastmap was found.1485 * UBI_BAD_FASTMAP denotes that the found fastmap was invalid.1486 */1487static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info **ai)1488{1489 int err, pnum;1490 struct ubi_attach_info *scan_ai;1491 1492 err = -ENOMEM;1493 1494 scan_ai = alloc_ai();1495 if (!scan_ai)1496 goto out;1497 1498 scan_ai->ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);1499 if (!scan_ai->ech)1500 goto out_ai;1501 1502 scan_ai->vidb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);1503 if (!scan_ai->vidb)1504 goto out_ech;1505 1506 for (pnum = 0; pnum < UBI_FM_MAX_START; pnum++) {1507 cond_resched();1508 1509 dbg_gen("process PEB %d", pnum);1510 err = scan_peb(ubi, scan_ai, pnum, true);1511 if (err < 0)1512 goto out_vidh;1513 }1514 1515 ubi_free_vid_buf(scan_ai->vidb);1516 kfree(scan_ai->ech);1517 1518 if (scan_ai->force_full_scan)1519 err = UBI_NO_FASTMAP;1520 else1521 err = ubi_scan_fastmap(ubi, *ai, scan_ai);1522 1523 if (err) {1524 /*1525 * Didn't attach via fastmap, do a full scan but reuse what1526 * we've aready scanned.1527 */1528 destroy_ai(*ai);1529 *ai = scan_ai;1530 } else1531 destroy_ai(scan_ai);1532 1533 return err;1534 1535out_vidh:1536 ubi_free_vid_buf(scan_ai->vidb);1537out_ech:1538 kfree(scan_ai->ech);1539out_ai:1540 destroy_ai(scan_ai);1541out:1542 return err;1543}1544 1545#endif1546 1547/**1548 * ubi_attach - attach an MTD device.1549 * @ubi: UBI device descriptor1550 * @force_scan: if set to non-zero attach by scanning1551 *1552 * This function returns zero in case of success and a negative error code in1553 * case of failure.1554 */1555int ubi_attach(struct ubi_device *ubi, int force_scan)1556{1557 int err;1558 struct ubi_attach_info *ai;1559 1560 ai = alloc_ai();1561 if (!ai)1562 return -ENOMEM;1563 1564#ifdef CONFIG_MTD_UBI_FASTMAP1565 /* On small flash devices we disable fastmap in any case. */1566 if ((int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd) <= UBI_FM_MAX_START) {1567 ubi->fm_disabled = 1;1568 force_scan = 1;1569 }1570 1571 if (force_scan)1572 err = scan_all(ubi, ai, 0);1573 else {1574 err = scan_fast(ubi, &ai);1575 if (err > 0 || mtd_is_eccerr(err)) {1576 if (err != UBI_NO_FASTMAP) {1577 destroy_ai(ai);1578 ai = alloc_ai();1579 if (!ai)1580 return -ENOMEM;1581 1582 err = scan_all(ubi, ai, 0);1583 } else {1584 err = scan_all(ubi, ai, UBI_FM_MAX_START);1585 }1586 }1587 }1588#else1589 err = scan_all(ubi, ai, 0);1590#endif1591 if (err)1592 goto out_ai;1593 1594 ubi->bad_peb_count = ai->bad_peb_count;1595 ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;1596 ubi->corr_peb_count = ai->corr_peb_count;1597 ubi->max_ec = ai->max_ec;1598 ubi->mean_ec = ai->mean_ec;1599 dbg_gen("max. sequence number: %llu", ai->max_sqnum);1600 1601 err = ubi_read_volume_table(ubi, ai);1602 if (err)1603 goto out_ai;1604 1605 err = ubi_wl_init(ubi, ai);1606 if (err)1607 goto out_vtbl;1608 1609 err = ubi_eba_init(ubi, ai);1610 if (err)1611 goto out_wl;1612 1613#ifdef CONFIG_MTD_UBI_FASTMAP1614 if (ubi->fm && ubi_dbg_chk_fastmap(ubi)) {1615 struct ubi_attach_info *scan_ai;1616 1617 scan_ai = alloc_ai();1618 if (!scan_ai) {1619 err = -ENOMEM;1620 goto out_wl;1621 }1622 1623 err = scan_all(ubi, scan_ai, 0);1624 if (err) {1625 destroy_ai(scan_ai);1626 goto out_wl;1627 }1628 1629 err = self_check_eba(ubi, ai, scan_ai);1630 destroy_ai(scan_ai);1631 1632 if (err)1633 goto out_wl;1634 }1635#endif1636 1637 destroy_ai(ai);1638 return 0;1639 1640out_wl:1641 ubi_wl_close(ubi);1642out_vtbl:1643 ubi_free_all_volumes(ubi);1644 vfree(ubi->vtbl);1645out_ai:1646 destroy_ai(ai);1647 return err;1648}1649 1650/**1651 * self_check_ai - check the attaching information.1652 * @ubi: UBI device description object1653 * @ai: attaching information1654 *1655 * This function returns zero if the attaching information is all right, and a1656 * negative error code if not or if an error occurred.1657 */1658static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai)1659{1660 struct ubi_vid_io_buf *vidb = ai->vidb;1661 struct ubi_vid_hdr *vidh = ubi_get_vid_hdr(vidb);1662 int pnum, err, vols_found = 0;1663 struct rb_node *rb1, *rb2;1664 struct ubi_ainf_volume *av;1665 struct ubi_ainf_peb *aeb, *last_aeb;1666 uint8_t *buf;1667 1668 if (!ubi_dbg_chk_gen(ubi))1669 return 0;1670 1671 /*1672 * At first, check that attaching information is OK.1673 */1674 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {1675 int leb_count = 0;1676 1677 cond_resched();1678 1679 vols_found += 1;1680 1681 if (ai->is_empty) {1682 ubi_err(ubi, "bad is_empty flag");1683 goto bad_av;1684 }1685 1686 if (av->vol_id < 0 || av->highest_lnum < 0 ||1687 av->leb_count < 0 || av->vol_type < 0 || av->used_ebs < 0 ||1688 av->data_pad < 0 || av->last_data_size < 0) {1689 ubi_err(ubi, "negative values");1690 goto bad_av;1691 }1692 1693 if (av->vol_id >= UBI_MAX_VOLUMES &&1694 av->vol_id < UBI_INTERNAL_VOL_START) {1695 ubi_err(ubi, "bad vol_id");1696 goto bad_av;1697 }1698 1699 if (av->vol_id > ai->highest_vol_id) {1700 ubi_err(ubi, "highest_vol_id is %d, but vol_id %d is there",1701 ai->highest_vol_id, av->vol_id);1702 goto out;1703 }1704 1705 if (av->vol_type != UBI_DYNAMIC_VOLUME &&1706 av->vol_type != UBI_STATIC_VOLUME) {1707 ubi_err(ubi, "bad vol_type");1708 goto bad_av;1709 }1710 1711 if (av->data_pad > ubi->leb_size / 2) {1712 ubi_err(ubi, "bad data_pad");1713 goto bad_av;1714 }1715 1716 last_aeb = NULL;1717 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) {1718 cond_resched();1719 1720 last_aeb = aeb;1721 leb_count += 1;1722 1723 if (aeb->pnum < 0 || aeb->ec < 0) {1724 ubi_err(ubi, "negative values");1725 goto bad_aeb;1726 }1727 1728 if (aeb->ec < ai->min_ec) {1729 ubi_err(ubi, "bad ai->min_ec (%d), %d found",1730 ai->min_ec, aeb->ec);1731 goto bad_aeb;1732 }1733 1734 if (aeb->ec > ai->max_ec) {1735 ubi_err(ubi, "bad ai->max_ec (%d), %d found",1736 ai->max_ec, aeb->ec);1737 goto bad_aeb;1738 }1739 1740 if (aeb->pnum >= ubi->peb_count) {1741 ubi_err(ubi, "too high PEB number %d, total PEBs %d",1742 aeb->pnum, ubi->peb_count);1743 goto bad_aeb;1744 }1745 1746 if (av->vol_type == UBI_STATIC_VOLUME) {1747 if (aeb->lnum >= av->used_ebs) {1748 ubi_err(ubi, "bad lnum or used_ebs");1749 goto bad_aeb;1750 }1751 } else {1752 if (av->used_ebs != 0) {1753 ubi_err(ubi, "non-zero used_ebs");1754 goto bad_aeb;1755 }1756 }1757 1758 if (aeb->lnum > av->highest_lnum) {1759 ubi_err(ubi, "incorrect highest_lnum or lnum");1760 goto bad_aeb;1761 }1762 }1763 1764 if (av->leb_count != leb_count) {1765 ubi_err(ubi, "bad leb_count, %d objects in the tree",1766 leb_count);1767 goto bad_av;1768 }1769 1770 if (!last_aeb)1771 continue;1772 1773 aeb = last_aeb;1774 1775 if (aeb->lnum != av->highest_lnum) {1776 ubi_err(ubi, "bad highest_lnum");1777 goto bad_aeb;1778 }1779 }1780 1781 if (vols_found != ai->vols_found) {1782 ubi_err(ubi, "bad ai->vols_found %d, should be %d",1783 ai->vols_found, vols_found);1784 goto out;1785 }1786 1787 /* Check that attaching information is correct */1788 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {1789 last_aeb = NULL;1790 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) {1791 int vol_type;1792 1793 cond_resched();1794 1795 last_aeb = aeb;1796 1797 err = ubi_io_read_vid_hdr(ubi, aeb->pnum, vidb, 1);1798 if (err && err != UBI_IO_BITFLIPS) {1799 ubi_err(ubi, "VID header is not OK (%d)",1800 err);1801 if (err > 0)1802 err = -EIO;1803 return err;1804 }1805 1806 vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?1807 UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;1808 if (av->vol_type != vol_type) {1809 ubi_err(ubi, "bad vol_type");1810 goto bad_vid_hdr;1811 }1812 1813 if (aeb->sqnum != be64_to_cpu(vidh->sqnum)) {1814 ubi_err(ubi, "bad sqnum %llu", aeb->sqnum);1815 goto bad_vid_hdr;1816 }1817 1818 if (av->vol_id != be32_to_cpu(vidh->vol_id)) {1819 ubi_err(ubi, "bad vol_id %d", av->vol_id);1820 goto bad_vid_hdr;1821 }1822 1823 if (av->compat != vidh->compat) {1824 ubi_err(ubi, "bad compat %d", vidh->compat);1825 goto bad_vid_hdr;1826 }1827 1828 if (aeb->lnum != be32_to_cpu(vidh->lnum)) {1829 ubi_err(ubi, "bad lnum %d", aeb->lnum);1830 goto bad_vid_hdr;1831 }1832 1833 if (av->used_ebs != be32_to_cpu(vidh->used_ebs)) {1834 ubi_err(ubi, "bad used_ebs %d", av->used_ebs);1835 goto bad_vid_hdr;1836 }1837 1838 if (av->data_pad != be32_to_cpu(vidh->data_pad)) {1839 ubi_err(ubi, "bad data_pad %d", av->data_pad);1840 goto bad_vid_hdr;1841 }1842 }1843 1844 if (!last_aeb)1845 continue;1846 1847 if (av->highest_lnum != be32_to_cpu(vidh->lnum)) {1848 ubi_err(ubi, "bad highest_lnum %d", av->highest_lnum);1849 goto bad_vid_hdr;1850 }1851 1852 if (av->last_data_size != be32_to_cpu(vidh->data_size)) {1853 ubi_err(ubi, "bad last_data_size %d",1854 av->last_data_size);1855 goto bad_vid_hdr;1856 }1857 }1858 1859 /*1860 * Make sure that all the physical eraseblocks are in one of the lists1861 * or trees.1862 */1863 buf = kzalloc(ubi->peb_count, GFP_KERNEL);1864 if (!buf)1865 return -ENOMEM;1866 1867 for (pnum = 0; pnum < ubi->peb_count; pnum++) {1868 err = ubi_io_is_bad(ubi, pnum);1869 if (err < 0) {1870 kfree(buf);1871 return err;1872 } else if (err)1873 buf[pnum] = 1;1874 }1875 1876 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)1877 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)1878 buf[aeb->pnum] = 1;1879 1880 list_for_each_entry(aeb, &ai->free, u.list)1881 buf[aeb->pnum] = 1;1882 1883 list_for_each_entry(aeb, &ai->corr, u.list)1884 buf[aeb->pnum] = 1;1885 1886 list_for_each_entry(aeb, &ai->erase, u.list)1887 buf[aeb->pnum] = 1;1888 1889 list_for_each_entry(aeb, &ai->alien, u.list)1890 buf[aeb->pnum] = 1;1891 1892 err = 0;1893 for (pnum = 0; pnum < ubi->peb_count; pnum++)1894 if (!buf[pnum]) {1895 ubi_err(ubi, "PEB %d is not referred", pnum);1896 err = 1;1897 }1898 1899 kfree(buf);1900 if (err)1901 goto out;1902 return 0;1903 1904bad_aeb:1905 ubi_err(ubi, "bad attaching information about LEB %d", aeb->lnum);1906 ubi_dump_aeb(aeb, 0);1907 ubi_dump_av(av);1908 goto out;1909 1910bad_av:1911 ubi_err(ubi, "bad attaching information about volume %d", av->vol_id);1912 ubi_dump_av(av);1913 goto out;1914 1915bad_vid_hdr:1916 ubi_err(ubi, "bad attaching information about volume %d", av->vol_id);1917 ubi_dump_av(av);1918 ubi_dump_vid_hdr(vidh);1919 1920out:1921 dump_stack();1922 return -EINVAL;1923}1924