diff options
Diffstat (limited to 'drivers/mtd/ubi/attach.c')
| -rw-r--r-- | drivers/mtd/ubi/attach.c | 1923 |
1 files changed, 1923 insertions, 0 deletions
diff --git a/drivers/mtd/ubi/attach.c b/drivers/mtd/ubi/attach.c new file mode 100644 index 000000000..ae5abe492 --- /dev/null +++ b/drivers/mtd/ubi/attach.c @@ -0,0 +1,1923 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) International Business Machines Corp., 2006 + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * UBI attaching sub-system. + * + * This sub-system is responsible for attaching MTD devices and it also + * implements flash media scanning. + * + * The attaching information is represented by a &struct ubi_attach_info' + * object. Information about volumes is represented by &struct ubi_ainf_volume + * objects which are kept in volume RB-tree with root at the @volumes field. + * The RB-tree is indexed by the volume ID. + * + * Logical eraseblocks are represented by &struct ubi_ainf_peb objects. These + * objects are kept in per-volume RB-trees with the root at the corresponding + * &struct ubi_ainf_volume object. To put it differently, we keep an RB-tree of + * per-volume objects and each of these objects is the root of RB-tree of + * per-LEB objects. + * + * Corrupted physical eraseblocks are put to the @corr list, free physical + * eraseblocks are put to the @free list and the physical eraseblock to be + * erased are put to the @erase list. + * + * About corruptions + * ~~~~~~~~~~~~~~~~~ + * + * UBI protects EC and VID headers with CRC-32 checksums, so it can detect + * whether the headers are corrupted or not. Sometimes UBI also protects the + * data with CRC-32, e.g., when it executes the atomic LEB change operation, or + * when it moves the contents of a PEB for wear-leveling purposes. + * + * UBI tries to distinguish between 2 types of corruptions. + * + * 1. Corruptions caused by power cuts. These are expected corruptions and UBI + * tries to handle them gracefully, without printing too many warnings and + * error messages. The idea is that we do not lose important data in these + * cases - we may lose only the data which were being written to the media just + * before the power cut happened, and the upper layers (e.g., UBIFS) are + * supposed to handle such data losses (e.g., by using the FS journal). + * + * When UBI detects a corruption (CRC-32 mismatch) in a PEB, and it looks like + * the reason is a power cut, UBI puts this PEB to the @erase list, and all + * PEBs in the @erase list are scheduled for erasure later. + * + * 2. Unexpected corruptions which are not caused by power cuts. During + * attaching, such PEBs are put to the @corr list and UBI preserves them. + * Obviously, this lessens the amount of available PEBs, and if at some point + * UBI runs out of free PEBs, it switches to R/O mode. UBI also loudly informs + * about such PEBs every time the MTD device is attached. + * + * However, it is difficult to reliably distinguish between these types of + * corruptions and UBI's strategy is as follows (in case of attaching by + * scanning). UBI assumes corruption type 2 if the VID header is corrupted and + * the data area does not contain all 0xFFs, and there were no bit-flips or + * integrity errors (e.g., ECC errors in case of NAND) while reading the data + * area. Otherwise UBI assumes corruption type 1. So the decision criteria + * are as follows. + * o If the data area contains only 0xFFs, there are no data, and it is safe + * to just erase this PEB - this is corruption type 1. + * o If the data area has bit-flips or data integrity errors (ECC errors on + * NAND), it is probably a PEB which was being erased when power cut + * happened, so this is corruption type 1. However, this is just a guess, + * which might be wrong. + * o Otherwise this is corruption type 2. + */ + +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/crc32.h> +#include <linux/math64.h> +#include <linux/random.h> +#include "ubi.h" + +static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai); + +#define AV_FIND BIT(0) +#define AV_ADD BIT(1) +#define AV_FIND_OR_ADD (AV_FIND | AV_ADD) + +/** + * find_or_add_av - internal function to find a volume, add a volume or do + * both (find and add if missing). + * @ai: attaching information + * @vol_id: the requested volume ID + * @flags: a combination of the %AV_FIND and %AV_ADD flags describing the + * expected operation. If only %AV_ADD is set, -EEXIST is returned + * if the volume already exists. If only %AV_FIND is set, NULL is + * returned if the volume does not exist. And if both flags are + * set, the helper first tries to find an existing volume, and if + * it does not exist it creates a new one. + * @created: in value used to inform the caller whether it"s a newly created + * volume or not. + * + * This function returns a pointer to a volume description or an ERR_PTR if + * the operation failed. It can also return NULL if only %AV_FIND is set and + * the volume does not exist. + */ +static struct ubi_ainf_volume *find_or_add_av(struct ubi_attach_info *ai, + int vol_id, unsigned int flags, + bool *created) +{ + struct ubi_ainf_volume *av; + struct rb_node **p = &ai->volumes.rb_node, *parent = NULL; + + /* Walk the volume RB-tree to look if this volume is already present */ + while (*p) { + parent = *p; + av = rb_entry(parent, struct ubi_ainf_volume, rb); + + if (vol_id == av->vol_id) { + *created = false; + + if (!(flags & AV_FIND)) + return ERR_PTR(-EEXIST); + + return av; + } + + if (vol_id > av->vol_id) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + } + + if (!(flags & AV_ADD)) + return NULL; + + /* The volume is absent - add it */ + av = kzalloc(sizeof(*av), GFP_KERNEL); + if (!av) + return ERR_PTR(-ENOMEM); + + av->vol_id = vol_id; + + if (vol_id > ai->highest_vol_id) + ai->highest_vol_id = vol_id; + + rb_link_node(&av->rb, parent, p); + rb_insert_color(&av->rb, &ai->volumes); + ai->vols_found += 1; + *created = true; + dbg_bld("added volume %d", vol_id); + return av; +} + +/** + * ubi_find_or_add_av - search for a volume in the attaching information and + * add one if it does not exist. + * @ai: attaching information + * @vol_id: the requested volume ID + * @created: whether the volume has been created or not + * + * This function returns a pointer to the new volume description or an + * ERR_PTR if the operation failed. + */ +static struct ubi_ainf_volume *ubi_find_or_add_av(struct ubi_attach_info *ai, + int vol_id, bool *created) +{ + return find_or_add_av(ai, vol_id, AV_FIND_OR_ADD, created); +} + +/** + * ubi_alloc_aeb - allocate an aeb element + * @ai: attaching information + * @pnum: physical eraseblock number + * @ec: erase counter of the physical eraseblock + * + * Allocate an aeb object and initialize the pnum and ec information. + * vol_id and lnum are set to UBI_UNKNOWN, and the other fields are + * initialized to zero. + * Note that the element is not added in any list or RB tree. + */ +struct ubi_ainf_peb *ubi_alloc_aeb(struct ubi_attach_info *ai, int pnum, + int ec) +{ + struct ubi_ainf_peb *aeb; + + aeb = kmem_cache_zalloc(ai->aeb_slab_cache, GFP_KERNEL); + if (!aeb) + return NULL; + + aeb->pnum = pnum; + aeb->ec = ec; + aeb->vol_id = UBI_UNKNOWN; + aeb->lnum = UBI_UNKNOWN; + + return aeb; +} + +/** + * ubi_free_aeb - free an aeb element + * @ai: attaching information + * @aeb: the element to free + * + * Free an aeb object. The caller must have removed the element from any list + * or RB tree. + */ +void ubi_free_aeb(struct ubi_attach_info *ai, struct ubi_ainf_peb *aeb) +{ + kmem_cache_free(ai->aeb_slab_cache, aeb); +} + +/** + * add_to_list - add physical eraseblock to a list. + * @ai: attaching information + * @pnum: physical eraseblock number to add + * @vol_id: the last used volume id for the PEB + * @lnum: the last used LEB number for the PEB + * @ec: erase counter of the physical eraseblock + * @to_head: if not zero, add to the head of the list + * @list: the list to add to + * + * This function allocates a 'struct ubi_ainf_peb' object for physical + * eraseblock @pnum and adds it to the "free", "erase", or "alien" lists. + * It stores the @lnum and @vol_id alongside, which can both be + * %UBI_UNKNOWN if they are not available, not readable, or not assigned. + * If @to_head is not zero, PEB will be added to the head of the list, which + * basically means it will be processed first later. E.g., we add corrupted + * PEBs (corrupted due to power cuts) to the head of the erase list to make + * sure we erase them first and get rid of corruptions ASAP. This function + * returns zero in case of success and a negative error code in case of + * failure. + */ +static int add_to_list(struct ubi_attach_info *ai, int pnum, int vol_id, + int lnum, int ec, int to_head, struct list_head *list) +{ + struct ubi_ainf_peb *aeb; + + if (list == &ai->free) { + dbg_bld("add to free: PEB %d, EC %d", pnum, ec); + } else if (list == &ai->erase) { + dbg_bld("add to erase: PEB %d, EC %d", pnum, ec); + } else if (list == &ai->alien) { + dbg_bld("add to alien: PEB %d, EC %d", pnum, ec); + ai->alien_peb_count += 1; + } else + BUG(); + + aeb = ubi_alloc_aeb(ai, pnum, ec); + if (!aeb) + return -ENOMEM; + + aeb->vol_id = vol_id; + aeb->lnum = lnum; + if (to_head) + list_add(&aeb->u.list, list); + else + list_add_tail(&aeb->u.list, list); + return 0; +} + +/** + * add_corrupted - add a corrupted physical eraseblock. + * @ai: attaching information + * @pnum: physical eraseblock number to add + * @ec: erase counter of the physical eraseblock + * + * This function allocates a 'struct ubi_ainf_peb' object for a corrupted + * physical eraseblock @pnum and adds it to the 'corr' list. The corruption + * was presumably not caused by a power cut. Returns zero in case of success + * and a negative error code in case of failure. + */ +static int add_corrupted(struct ubi_attach_info *ai, int pnum, int ec) +{ + struct ubi_ainf_peb *aeb; + + dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec); + + aeb = ubi_alloc_aeb(ai, pnum, ec); + if (!aeb) + return -ENOMEM; + + ai->corr_peb_count += 1; + list_add(&aeb->u.list, &ai->corr); + return 0; +} + +/** + * add_fastmap - add a Fastmap related physical eraseblock. + * @ai: attaching information + * @pnum: physical eraseblock number the VID header came from + * @vid_hdr: the volume identifier header + * @ec: erase counter of the physical eraseblock + * + * This function allocates a 'struct ubi_ainf_peb' object for a Fastamp + * physical eraseblock @pnum and adds it to the 'fastmap' list. + * Such blocks can be Fastmap super and data blocks from both the most + * recent Fastmap we're attaching from or from old Fastmaps which will + * be erased. + */ +static int add_fastmap(struct ubi_attach_info *ai, int pnum, + struct ubi_vid_hdr *vid_hdr, int ec) +{ + struct ubi_ainf_peb *aeb; + + aeb = ubi_alloc_aeb(ai, pnum, ec); + if (!aeb) + return -ENOMEM; + + aeb->vol_id = be32_to_cpu(vid_hdr->vol_id); + aeb->sqnum = be64_to_cpu(vid_hdr->sqnum); + list_add(&aeb->u.list, &ai->fastmap); + + dbg_bld("add to fastmap list: PEB %d, vol_id %d, sqnum: %llu", pnum, + aeb->vol_id, aeb->sqnum); + + return 0; +} + +/** + * validate_vid_hdr - check volume identifier header. + * @ubi: UBI device description object + * @vid_hdr: the volume identifier header to check + * @av: information about the volume this logical eraseblock belongs to + * @pnum: physical eraseblock number the VID header came from + * + * This function checks that data stored in @vid_hdr is consistent. Returns + * non-zero if an inconsistency was found and zero if not. + * + * Note, UBI does sanity check of everything it reads from the flash media. + * Most of the checks are done in the I/O sub-system. Here we check that the + * information in the VID header is consistent to the information in other VID + * headers of the same volume. + */ +static int validate_vid_hdr(const struct ubi_device *ubi, + const struct ubi_vid_hdr *vid_hdr, + const struct ubi_ainf_volume *av, int pnum) +{ + int vol_type = vid_hdr->vol_type; + int vol_id = be32_to_cpu(vid_hdr->vol_id); + int used_ebs = be32_to_cpu(vid_hdr->used_ebs); + int data_pad = be32_to_cpu(vid_hdr->data_pad); + + if (av->leb_count != 0) { + int av_vol_type; + + /* + * This is not the first logical eraseblock belonging to this + * volume. Ensure that the data in its VID header is consistent + * to the data in previous logical eraseblock headers. + */ + + if (vol_id != av->vol_id) { + ubi_err(ubi, "inconsistent vol_id"); + goto bad; + } + + if (av->vol_type == UBI_STATIC_VOLUME) + av_vol_type = UBI_VID_STATIC; + else + av_vol_type = UBI_VID_DYNAMIC; + + if (vol_type != av_vol_type) { + ubi_err(ubi, "inconsistent vol_type"); + goto bad; + } + + if (used_ebs != av->used_ebs) { + ubi_err(ubi, "inconsistent used_ebs"); + goto bad; + } + + if (data_pad != av->data_pad) { + ubi_err(ubi, "inconsistent data_pad"); + goto bad; + } + } + + return 0; + +bad: + ubi_err(ubi, "inconsistent VID header at PEB %d", pnum); + ubi_dump_vid_hdr(vid_hdr); + ubi_dump_av(av); + return -EINVAL; +} + +/** + * add_volume - add volume to the attaching information. + * @ai: attaching information + * @vol_id: ID of the volume to add + * @pnum: physical eraseblock number + * @vid_hdr: volume identifier header + * + * If the volume corresponding to the @vid_hdr logical eraseblock is already + * present in the attaching information, this function does nothing. Otherwise + * it adds corresponding volume to the attaching information. Returns a pointer + * to the allocated "av" object in case of success and a negative error code in + * case of failure. + */ +static struct ubi_ainf_volume *add_volume(struct ubi_attach_info *ai, + int vol_id, int pnum, + const struct ubi_vid_hdr *vid_hdr) +{ + struct ubi_ainf_volume *av; + bool created; + + ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id)); + + av = ubi_find_or_add_av(ai, vol_id, &created); + if (IS_ERR(av) || !created) + return av; + + av->used_ebs = be32_to_cpu(vid_hdr->used_ebs); + av->data_pad = be32_to_cpu(vid_hdr->data_pad); + av->compat = vid_hdr->compat; + av->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME + : UBI_STATIC_VOLUME; + + return av; +} + +/** + * ubi_compare_lebs - find out which logical eraseblock is newer. + * @ubi: UBI device description object + * @aeb: first logical eraseblock to compare + * @pnum: physical eraseblock number of the second logical eraseblock to + * compare + * @vid_hdr: volume identifier header of the second logical eraseblock + * + * This function compares 2 copies of a LEB and informs which one is newer. In + * case of success this function returns a positive value, in case of failure, a + * negative error code is returned. The success return codes use the following + * bits: + * o bit 0 is cleared: the first PEB (described by @aeb) is newer than the + * second PEB (described by @pnum and @vid_hdr); + * o bit 0 is set: the second PEB is newer; + * o bit 1 is cleared: no bit-flips were detected in the newer LEB; + * o bit 1 is set: bit-flips were detected in the newer LEB; + * o bit 2 is cleared: the older LEB is not corrupted; + * o bit 2 is set: the older LEB is corrupted. + */ +int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb, + int pnum, const struct ubi_vid_hdr *vid_hdr) +{ + int len, err, second_is_newer, bitflips = 0, corrupted = 0; + uint32_t data_crc, crc; + struct ubi_vid_io_buf *vidb = NULL; + unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum); + + if (sqnum2 == aeb->sqnum) { + /* + * This must be a really ancient UBI image which has been + * created before sequence numbers support has been added. At + * that times we used 32-bit LEB versions stored in logical + * eraseblocks. That was before UBI got into mainline. We do not + * support these images anymore. Well, those images still work, + * but only if no unclean reboots happened. + */ + ubi_err(ubi, "unsupported on-flash UBI format"); + return -EINVAL; + } + + /* Obviously the LEB with lower sequence counter is older */ + second_is_newer = (sqnum2 > aeb->sqnum); + + /* + * Now we know which copy is newer. If the copy flag of the PEB with + * newer version is not set, then we just return, otherwise we have to + * check data CRC. For the second PEB we already have the VID header, + * for the first one - we'll need to re-read it from flash. + * + * Note: this may be optimized so that we wouldn't read twice. + */ + + if (second_is_newer) { + if (!vid_hdr->copy_flag) { + /* It is not a copy, so it is newer */ + dbg_bld("second PEB %d is newer, copy_flag is unset", + pnum); + return 1; + } + } else { + if (!aeb->copy_flag) { + /* It is not a copy, so it is newer */ + dbg_bld("first PEB %d is newer, copy_flag is unset", + pnum); + return bitflips << 1; + } + + vidb = ubi_alloc_vid_buf(ubi, GFP_KERNEL); + if (!vidb) + return -ENOMEM; + + pnum = aeb->pnum; + err = ubi_io_read_vid_hdr(ubi, pnum, vidb, 0); + if (err) { + if (err == UBI_IO_BITFLIPS) + bitflips = 1; + else { + ubi_err(ubi, "VID of PEB %d header is bad, but it was OK earlier, err %d", + pnum, err); + if (err > 0) + err = -EIO; + + goto out_free_vidh; + } + } + + vid_hdr = ubi_get_vid_hdr(vidb); + } + + /* Read the data of the copy and check the CRC */ + + len = be32_to_cpu(vid_hdr->data_size); + + mutex_lock(&ubi->buf_mutex); + err = ubi_io_read_data(ubi, ubi->peb_buf, pnum, 0, len); + if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err)) + goto out_unlock; + + data_crc = be32_to_cpu(vid_hdr->data_crc); + crc = crc32(UBI_CRC32_INIT, ubi->peb_buf, len); + if (crc != data_crc) { + dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x", + pnum, crc, data_crc); + corrupted = 1; + bitflips = 0; + second_is_newer = !second_is_newer; + } else { + dbg_bld("PEB %d CRC is OK", pnum); + bitflips |= !!err; + } + mutex_unlock(&ubi->buf_mutex); + + ubi_free_vid_buf(vidb); + + if (second_is_newer) + dbg_bld("second PEB %d is newer, copy_flag is set", pnum); + else + dbg_bld("first PEB %d is newer, copy_flag is set", pnum); + + return second_is_newer | (bitflips << 1) | (corrupted << 2); + +out_unlock: + mutex_unlock(&ubi->buf_mutex); +out_free_vidh: + ubi_free_vid_buf(vidb); + return err; +} + +/** + * ubi_add_to_av - add used physical eraseblock to the attaching information. + * @ubi: UBI device description object + * @ai: attaching information + * @pnum: the physical eraseblock number + * @ec: erase counter + * @vid_hdr: the volume identifier header + * @bitflips: if bit-flips were detected when this physical eraseblock was read + * + * This function adds information about a used physical eraseblock to the + * 'used' tree of the corresponding volume. The function is rather complex + * because it has to handle cases when this is not the first physical + * eraseblock belonging to the same logical eraseblock, and the newer one has + * to be picked, while the older one has to be dropped. This function returns + * zero in case of success and a negative error code in case of failure. + */ +int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum, + int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips) +{ + int err, vol_id, lnum; + unsigned long long sqnum; + struct ubi_ainf_volume *av; + struct ubi_ainf_peb *aeb; + struct rb_node **p, *parent = NULL; + + vol_id = be32_to_cpu(vid_hdr->vol_id); + lnum = be32_to_cpu(vid_hdr->lnum); + sqnum = be64_to_cpu(vid_hdr->sqnum); + + dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d", + pnum, vol_id, lnum, ec, sqnum, bitflips); + + av = add_volume(ai, vol_id, pnum, vid_hdr); + if (IS_ERR(av)) + return PTR_ERR(av); + + if (ai->max_sqnum < sqnum) + ai->max_sqnum = sqnum; + + /* + * Walk the RB-tree of logical eraseblocks of volume @vol_id to look + * if this is the first instance of this logical eraseblock or not. + */ + p = &av->root.rb_node; + while (*p) { + int cmp_res; + + parent = *p; + aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb); + if (lnum != aeb->lnum) { + if (lnum < aeb->lnum) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + continue; + } + + /* + * There is already a physical eraseblock describing the same + * logical eraseblock present. + */ + + dbg_bld("this LEB already exists: PEB %d, sqnum %llu, EC %d", + aeb->pnum, aeb->sqnum, aeb->ec); + + /* + * Make sure that the logical eraseblocks have different + * sequence numbers. Otherwise the image is bad. + * + * However, if the sequence number is zero, we assume it must + * be an ancient UBI image from the era when UBI did not have + * sequence numbers. We still can attach these images, unless + * there is a need to distinguish between old and new + * eraseblocks, in which case we'll refuse the image in + * 'ubi_compare_lebs()'. In other words, we attach old clean + * images, but refuse attaching old images with duplicated + * logical eraseblocks because there was an unclean reboot. + */ + if (aeb->sqnum == sqnum && sqnum != 0) { + ubi_err(ubi, "two LEBs with same sequence number %llu", + sqnum); + ubi_dump_aeb(aeb, 0); + ubi_dump_vid_hdr(vid_hdr); + return -EINVAL; + } + + /* + * Now we have to drop the older one and preserve the newer + * one. + */ + cmp_res = ubi_compare_lebs(ubi, aeb, pnum, vid_hdr); + if (cmp_res < 0) + return cmp_res; + + if (cmp_res & 1) { + /* + * This logical eraseblock is newer than the one + * found earlier. + */ + err = validate_vid_hdr(ubi, vid_hdr, av, pnum); + if (err) + return err; + + err = add_to_list(ai, aeb->pnum, aeb->vol_id, + aeb->lnum, aeb->ec, cmp_res & 4, + &ai->erase); + if (err) + return err; + + aeb->ec = ec; + aeb->pnum = pnum; + aeb->vol_id = vol_id; + aeb->lnum = lnum; + aeb->scrub = ((cmp_res & 2) || bitflips); + aeb->copy_flag = vid_hdr->copy_flag; + aeb->sqnum = sqnum; + + if (av->highest_lnum == lnum) + av->last_data_size = + be32_to_cpu(vid_hdr->data_size); + + return 0; + } else { + /* + * This logical eraseblock is older than the one found + * previously. + */ + return add_to_list(ai, pnum, vol_id, lnum, ec, + cmp_res & 4, &ai->erase); + } + } + + /* + * We've met this logical eraseblock for the first time, add it to the + * attaching information. + */ + + err = validate_vid_hdr(ubi, vid_hdr, av, pnum); + if (err) + return err; + + aeb = ubi_alloc_aeb(ai, pnum, ec); + if (!aeb) + return -ENOMEM; + + aeb->vol_id = vol_id; + aeb->lnum = lnum; + aeb->scrub = bitflips; + aeb->copy_flag = vid_hdr->copy_flag; + aeb->sqnum = sqnum; + + if (av->highest_lnum <= lnum) { + av->highest_lnum = lnum; + av->last_data_size = be32_to_cpu(vid_hdr->data_size); + } + + av->leb_count += 1; + rb_link_node(&aeb->u.rb, parent, p); + rb_insert_color(&aeb->u.rb, &av->root); + return 0; +} + +/** + * ubi_add_av - add volume to the attaching information. + * @ai: attaching information + * @vol_id: the requested volume ID + * + * This function returns a pointer to the new volume description or an + * ERR_PTR if the operation failed. + */ +struct ubi_ainf_volume *ubi_add_av(struct ubi_attach_info *ai, int vol_id) +{ + bool created; + + return find_or_add_av(ai, vol_id, AV_ADD, &created); +} + +/** + * ubi_find_av - find volume in the attaching information. + * @ai: attaching information + * @vol_id: the requested volume ID + * + * This function returns a pointer to the volume description or %NULL if there + * are no data about this volume in the attaching information. + */ +struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai, + int vol_id) +{ + bool created; + + return find_or_add_av((struct ubi_attach_info *)ai, vol_id, AV_FIND, + &created); +} + +static void destroy_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av, + struct list_head *list); + +/** + * ubi_remove_av - delete attaching information about a volume. + * @ai: attaching information + * @av: the volume attaching information to delete + */ +void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av) +{ + dbg_bld("remove attaching information about volume %d", av->vol_id); + + rb_erase(&av->rb, &ai->volumes); + destroy_av(ai, av, &ai->erase); + ai->vols_found -= 1; +} + +/** + * early_erase_peb - erase a physical eraseblock. + * @ubi: UBI device description object + * @ai: attaching information + * @pnum: physical eraseblock number to erase; + * @ec: erase counter value to write (%UBI_UNKNOWN if it is unknown) + * + * This function erases physical eraseblock 'pnum', and writes the erase + * counter header to it. This function should only be used on UBI device + * initialization stages, when the EBA sub-system had not been yet initialized. + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int early_erase_peb(struct ubi_device *ubi, + const struct ubi_attach_info *ai, int pnum, int ec) +{ + int err; + struct ubi_ec_hdr *ec_hdr; + + if ((long long)ec >= UBI_MAX_ERASECOUNTER) { + /* + * Erase counter overflow. Upgrade UBI and use 64-bit + * erase counters internally. + */ + ubi_err(ubi, "erase counter overflow at PEB %d, EC %d", + pnum, ec); + return -EINVAL; + } + + ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL); + if (!ec_hdr) + return -ENOMEM; + + ec_hdr->ec = cpu_to_be64(ec); + + err = ubi_io_sync_erase(ubi, pnum, 0); + if (err < 0) + goto out_free; + + err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr); + +out_free: + kfree(ec_hdr); + return err; +} + +/** + * ubi_early_get_peb - get a free physical eraseblock. + * @ubi: UBI device description object + * @ai: attaching information + * + * This function returns a free physical eraseblock. It is supposed to be + * called on the UBI initialization stages when the wear-leveling sub-system is + * not initialized yet. This function picks a physical eraseblocks from one of + * the lists, writes the EC header if it is needed, and removes it from the + * list. + * + * This function returns a pointer to the "aeb" of the found free PEB in case + * of success and an error code in case of failure. + */ +struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi, + struct ubi_attach_info *ai) +{ + int err = 0; + struct ubi_ainf_peb *aeb, *tmp_aeb; + + if (!list_empty(&ai->free)) { + aeb = list_entry(ai->free.next, struct ubi_ainf_peb, u.list); + list_del(&aeb->u.list); + dbg_bld("return free PEB %d, EC %d", aeb->pnum, aeb->ec); + return aeb; + } + + /* + * We try to erase the first physical eraseblock from the erase list + * and pick it if we succeed, or try to erase the next one if not. And + * so forth. We don't want to take care about bad eraseblocks here - + * they'll be handled later. + */ + list_for_each_entry_safe(aeb, tmp_aeb, &ai->erase, u.list) { + if (aeb->ec == UBI_UNKNOWN) + aeb->ec = ai->mean_ec; + + err = early_erase_peb(ubi, ai, aeb->pnum, aeb->ec+1); + if (err) + continue; + + aeb->ec += 1; + list_del(&aeb->u.list); + dbg_bld("return PEB %d, EC %d", aeb->pnum, aeb->ec); + return aeb; + } + + ubi_err(ubi, "no free eraseblocks"); + return ERR_PTR(-ENOSPC); +} + +/** + * check_corruption - check the data area of PEB. + * @ubi: UBI device description object + * @vid_hdr: the (corrupted) VID header of this PEB + * @pnum: the physical eraseblock number to check + * + * This is a helper function which is used to distinguish between VID header + * corruptions caused by power cuts and other reasons. If the PEB contains only + * 0xFF bytes in the data area, the VID header is most probably corrupted + * because of a power cut (%0 is returned in this case). Otherwise, it was + * probably corrupted for some other reasons (%1 is returned in this case). A + * negative error code is returned if a read error occurred. + * + * If the corruption reason was a power cut, UBI can safely erase this PEB. + * Otherwise, it should preserve it to avoid possibly destroying important + * information. + */ +static int check_corruption(struct ubi_device *ubi, struct ubi_vid_hdr *vid_hdr, + int pnum) +{ + int err; + + mutex_lock(&ubi->buf_mutex); + memset(ubi->peb_buf, 0x00, ubi->leb_size); + + err = ubi_io_read(ubi, ubi->peb_buf, pnum, ubi->leb_start, + ubi->leb_size); + if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) { + /* + * Bit-flips or integrity errors while reading the data area. + * It is difficult to say for sure what type of corruption is + * this, but presumably a power cut happened while this PEB was + * erased, so it became unstable and corrupted, and should be + * erased. + */ + err = 0; + goto out_unlock; + } + + if (err) + goto out_unlock; + + if (ubi_check_pattern(ubi->peb_buf, 0xFF, ubi->leb_size)) + goto out_unlock; + + ubi_err(ubi, "PEB %d contains corrupted VID header, and the data does not contain all 0xFF", + pnum); + ubi_err(ubi, "this may be a non-UBI PEB or a severe VID header corruption which requires manual inspection"); + ubi_dump_vid_hdr(vid_hdr); + pr_err("hexdump of PEB %d offset %d, length %d", + pnum, ubi->leb_start, ubi->leb_size); + ubi_dbg_print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, + ubi->peb_buf, ubi->leb_size, 1); + err = 1; + +out_unlock: + mutex_unlock(&ubi->buf_mutex); + return err; +} + +static bool vol_ignored(int vol_id) +{ + switch (vol_id) { + case UBI_LAYOUT_VOLUME_ID: + return true; + } + +#ifdef CONFIG_MTD_UBI_FASTMAP + return ubi_is_fm_vol(vol_id); +#else + return false; +#endif +} + +/** + * scan_peb - scan and process UBI headers of a PEB. + * @ubi: UBI device description object + * @ai: attaching information + * @pnum: the physical eraseblock number + * @fast: true if we're scanning for a Fastmap + * + * This function reads UBI headers of PEB @pnum, checks them, and adds + * information about this PEB to the corresponding list or RB-tree in the + * "attaching info" structure. Returns zero if the physical eraseblock was + * successfully handled and a negative error code in case of failure. + */ +static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai, + int pnum, bool fast) +{ + struct ubi_ec_hdr *ech = ai->ech; + struct ubi_vid_io_buf *vidb = ai->vidb; + struct ubi_vid_hdr *vidh = ubi_get_vid_hdr(vidb); + long long ec; + int err, bitflips = 0, vol_id = -1, ec_err = 0; + + dbg_bld("scan PEB %d", pnum); + + /* Skip bad physical eraseblocks */ + err = ubi_io_is_bad(ubi, pnum); + if (err < 0) + return err; + else if (err) { + ai->bad_peb_count += 1; + return 0; + } + + err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0); + if (err < 0) + return err; + switch (err) { + case 0: + break; + case UBI_IO_BITFLIPS: + bitflips = 1; + break; + case UBI_IO_FF: + ai->empty_peb_count += 1; + return add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN, + UBI_UNKNOWN, 0, &ai->erase); + case UBI_IO_FF_BITFLIPS: + ai->empty_peb_count += 1; + return add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN, + UBI_UNKNOWN, 1, &ai->erase); + case UBI_IO_BAD_HDR_EBADMSG: + case UBI_IO_BAD_HDR: + /* + * We have to also look at the VID header, possibly it is not + * corrupted. Set %bitflips flag in order to make this PEB be + * moved and EC be re-created. + */ + ec_err = err; + ec = UBI_UNKNOWN; + bitflips = 1; + break; + default: + ubi_err(ubi, "'ubi_io_read_ec_hdr()' returned unknown code %d", + err); + return -EINVAL; + } + + if (!ec_err) { + int image_seq; + + /* Make sure UBI version is OK */ + if (ech->version != UBI_VERSION) { + ubi_err(ubi, "this UBI version is %d, image version is %d", + UBI_VERSION, (int)ech->version); + return -EINVAL; + } + + ec = be64_to_cpu(ech->ec); + if (ec > UBI_MAX_ERASECOUNTER) { + /* + * Erase counter overflow. The EC headers have 64 bits + * reserved, but we anyway make use of only 31 bit + * values, as this seems to be enough for any existing + * flash. Upgrade UBI and use 64-bit erase counters + * internally. + */ + ubi_err(ubi, "erase counter overflow, max is %d", + UBI_MAX_ERASECOUNTER); + ubi_dump_ec_hdr(ech); + return -EINVAL; + } + + /* + * Make sure that all PEBs have the same image sequence number. + * This allows us to detect situations when users flash UBI + * images incorrectly, so that the flash has the new UBI image + * and leftovers from the old one. This feature was added + * relatively recently, and the sequence number was always + * zero, because old UBI implementations always set it to zero. + * For this reasons, we do not panic if some PEBs have zero + * sequence number, while other PEBs have non-zero sequence + * number. + */ + image_seq = be32_to_cpu(ech->image_seq); + if (!ubi->image_seq) + ubi->image_seq = image_seq; + if (image_seq && ubi->image_seq != image_seq) { + ubi_err(ubi, "bad image sequence number %d in PEB %d, expected %d", + image_seq, pnum, ubi->image_seq); + ubi_dump_ec_hdr(ech); + return -EINVAL; + } + } + + /* OK, we've done with the EC header, let's look at the VID header */ + + err = ubi_io_read_vid_hdr(ubi, pnum, vidb, 0); + if (err < 0) + return err; + switch (err) { + case 0: + break; + case UBI_IO_BITFLIPS: + bitflips = 1; + break; + case UBI_IO_BAD_HDR_EBADMSG: + if (ec_err == UBI_IO_BAD_HDR_EBADMSG) + /* + * Both EC and VID headers are corrupted and were read + * with data integrity error, probably this is a bad + * PEB, bit it is not marked as bad yet. This may also + * be a result of power cut during erasure. + */ + ai->maybe_bad_peb_count += 1; + fallthrough; + case UBI_IO_BAD_HDR: + /* + * If we're facing a bad VID header we have to drop *all* + * Fastmap data structures we find. The most recent Fastmap + * could be bad and therefore there is a chance that we attach + * from an old one. On a fine MTD stack a PEB must not render + * bad all of a sudden, but the reality is different. + * So, let's be paranoid and help finding the root cause by + * falling back to scanning mode instead of attaching with a + * bad EBA table and cause data corruption which is hard to + * analyze. + */ + if (fast) + ai->force_full_scan = 1; + + if (ec_err) + /* + * Both headers are corrupted. There is a possibility + * that this a valid UBI PEB which has corresponding + * LEB, but the headers are corrupted. However, it is + * impossible to distinguish it from a PEB which just + * contains garbage because of a power cut during erase + * operation. So we just schedule this PEB for erasure. + * + * Besides, in case of NOR flash, we deliberately + * corrupt both headers because NOR flash erasure is + * slow and can start from the end. + */ + err = 0; + else + /* + * The EC was OK, but the VID header is corrupted. We + * have to check what is in the data area. + */ + err = check_corruption(ubi, vidh, pnum); + + if (err < 0) + return err; + else if (!err) + /* This corruption is caused by a power cut */ + err = add_to_list(ai, pnum, UBI_UNKNOWN, + UBI_UNKNOWN, ec, 1, &ai->erase); + else + /* This is an unexpected corruption */ + err = add_corrupted(ai, pnum, ec); + if (err) + return err; + goto adjust_mean_ec; + case UBI_IO_FF_BITFLIPS: + err = add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN, + ec, 1, &ai->erase); + if (err) + return err; + goto adjust_mean_ec; + case UBI_IO_FF: + if (ec_err || bitflips) + err = add_to_list(ai, pnum, UBI_UNKNOWN, + UBI_UNKNOWN, ec, 1, &ai->erase); + else + err = add_to_list(ai, pnum, UBI_UNKNOWN, + UBI_UNKNOWN, ec, 0, &ai->free); + if (err) + return err; + goto adjust_mean_ec; + default: + ubi_err(ubi, "'ubi_io_read_vid_hdr()' returned unknown code %d", + err); + return -EINVAL; + } + + vol_id = be32_to_cpu(vidh->vol_id); + if (vol_id > UBI_MAX_VOLUMES && !vol_ignored(vol_id)) { + int lnum = be32_to_cpu(vidh->lnum); + + /* Unsupported internal volume */ + switch (vidh->compat) { + case UBI_COMPAT_DELETE: + ubi_msg(ubi, "\"delete\" compatible internal volume %d:%d found, will remove it", + vol_id, lnum); + + err = add_to_list(ai, pnum, vol_id, lnum, + ec, 1, &ai->erase); + if (err) + return err; + return 0; + + case UBI_COMPAT_RO: + ubi_msg(ubi, "read-only compatible internal volume %d:%d found, switch to read-only mode", + vol_id, lnum); + ubi->ro_mode = 1; + break; + + case UBI_COMPAT_PRESERVE: + ubi_msg(ubi, "\"preserve\" compatible internal volume %d:%d found", + vol_id, lnum); + err = add_to_list(ai, pnum, vol_id, lnum, + ec, 0, &ai->alien); + if (err) + return err; + return 0; + + case UBI_COMPAT_REJECT: + ubi_err(ubi, "incompatible internal volume %d:%d found", + vol_id, lnum); + return -EINVAL; + } + } + + if (ec_err) + ubi_warn(ubi, "valid VID header but corrupted EC header at PEB %d", + pnum); + + if (ubi_is_fm_vol(vol_id)) + err = add_fastmap(ai, pnum, vidh, ec); + else + err = ubi_add_to_av(ubi, ai, pnum, ec, vidh, bitflips); + + if (err) + return err; + +adjust_mean_ec: + if (!ec_err) { + ai->ec_sum += ec; + ai->ec_count += 1; + if (ec > ai->max_ec) + ai->max_ec = ec; + if (ec < ai->min_ec) + ai->min_ec = ec; + } + + return 0; +} + +/** + * late_analysis - analyze the overall situation with PEB. + * @ubi: UBI device description object + * @ai: attaching information + * + * This is a helper function which takes a look what PEBs we have after we + * gather information about all of them ("ai" is compete). It decides whether + * the flash is empty and should be formatted of whether there are too many + * corrupted PEBs and we should not attach this MTD device. Returns zero if we + * should proceed with attaching the MTD device, and %-EINVAL if we should not. + */ +static int late_analysis(struct ubi_device *ubi, struct ubi_attach_info *ai) +{ + struct ubi_ainf_peb *aeb; + int max_corr, peb_count; + + peb_count = ubi->peb_count - ai->bad_peb_count - ai->alien_peb_count; + max_corr = peb_count / 20 ?: 8; + + /* + * Few corrupted PEBs is not a problem and may be just a result of + * unclean reboots. However, many of them may indicate some problems + * with the flash HW or driver. + */ + if (ai->corr_peb_count) { + ubi_err(ubi, "%d PEBs are corrupted and preserved", + ai->corr_peb_count); + pr_err("Corrupted PEBs are:"); + list_for_each_entry(aeb, &ai->corr, u.list) + pr_cont(" %d", aeb->pnum); + pr_cont("\n"); + + /* + * If too many PEBs are corrupted, we refuse attaching, + * otherwise, only print a warning. + */ + if (ai->corr_peb_count >= max_corr) { + ubi_err(ubi, "too many corrupted PEBs, refusing"); + return -EINVAL; + } + } + + if (ai->empty_peb_count + ai->maybe_bad_peb_count == peb_count) { + /* + * All PEBs are empty, or almost all - a couple PEBs look like + * they may be bad PEBs which were not marked as bad yet. + * + * This piece of code basically tries to distinguish between + * the following situations: + * + * 1. Flash is empty, but there are few bad PEBs, which are not + * marked as bad so far, and which were read with error. We + * want to go ahead and format this flash. While formatting, + * the faulty PEBs will probably be marked as bad. + * + * 2. Flash contains non-UBI data and we do not want to format + * it and destroy possibly important information. + */ + if (ai->maybe_bad_peb_count <= 2) { + ai->is_empty = 1; + ubi_msg(ubi, "empty MTD device detected"); + get_random_bytes(&ubi->image_seq, + sizeof(ubi->image_seq)); + } else { + ubi_err(ubi, "MTD device is not UBI-formatted and possibly contains non-UBI data - refusing it"); + return -EINVAL; + } + + } + + return 0; +} + +/** + * destroy_av - free volume attaching information. + * @av: volume attaching information + * @ai: attaching information + * @list: put the aeb elements in there if !NULL, otherwise free them + * + * This function destroys the volume attaching information. + */ +static void destroy_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av, + struct list_head *list) +{ + struct ubi_ainf_peb *aeb; + struct rb_node *this = av->root.rb_node; + + while (this) { + if (this->rb_left) + this = this->rb_left; + else if (this->rb_right) + this = this->rb_right; + else { + aeb = rb_entry(this, struct ubi_ainf_peb, u.rb); + this = rb_parent(this); + if (this) { + if (this->rb_left == &aeb->u.rb) + this->rb_left = NULL; + else + this->rb_right = NULL; + } + + if (list) + list_add_tail(&aeb->u.list, list); + else + ubi_free_aeb(ai, aeb); + } + } + kfree(av); +} + +/** + * destroy_ai - destroy attaching information. + * @ai: attaching information + */ +static void destroy_ai(struct ubi_attach_info *ai) +{ + struct ubi_ainf_peb *aeb, *aeb_tmp; + struct ubi_ainf_volume *av; + struct rb_node *rb; + + list_for_each_entry_safe(aeb, aeb_tmp, &ai->alien, u.list) { + list_del(&aeb->u.list); + ubi_free_aeb(ai, aeb); + } + list_for_each_entry_safe(aeb, aeb_tmp, &ai->erase, u.list) { + list_del(&aeb->u.list); + ubi_free_aeb(ai, aeb); + } + list_for_each_entry_safe(aeb, aeb_tmp, &ai->corr, u.list) { + list_del(&aeb->u.list); + ubi_free_aeb(ai, aeb); + } + list_for_each_entry_safe(aeb, aeb_tmp, &ai->free, u.list) { + list_del(&aeb->u.list); + ubi_free_aeb(ai, aeb); + } + list_for_each_entry_safe(aeb, aeb_tmp, &ai->fastmap, u.list) { + list_del(&aeb->u.list); + ubi_free_aeb(ai, aeb); + } + + /* Destroy the volume RB-tree */ + rb = ai->volumes.rb_node; + while (rb) { + if (rb->rb_left) + rb = rb->rb_left; + else if (rb->rb_right) + rb = rb->rb_right; + else { + av = rb_entry(rb, struct ubi_ainf_volume, rb); + + rb = rb_parent(rb); + if (rb) { + if (rb->rb_left == &av->rb) + rb->rb_left = NULL; + else + rb->rb_right = NULL; + } + + destroy_av(ai, av, NULL); + } + } + + kmem_cache_destroy(ai->aeb_slab_cache); + kfree(ai); +} + +/** + * scan_all - scan entire MTD device. + * @ubi: UBI device description object + * @ai: attach info object + * @start: start scanning at this PEB + * + * This function does full scanning of an MTD device and returns complete + * information about it in form of a "struct ubi_attach_info" object. In case + * of failure, an error code is returned. + */ +static int scan_all(struct ubi_device *ubi, struct ubi_attach_info *ai, + int start) +{ + int err, pnum; + struct rb_node *rb1, *rb2; + struct ubi_ainf_volume *av; + struct ubi_ainf_peb *aeb; + + err = -ENOMEM; + + ai->ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL); + if (!ai->ech) + return err; + + ai->vidb = ubi_alloc_vid_buf(ubi, GFP_KERNEL); + if (!ai->vidb) + goto out_ech; + + for (pnum = start; pnum < ubi->peb_count; pnum++) { + cond_resched(); + + dbg_gen("process PEB %d", pnum); + err = scan_peb(ubi, ai, pnum, false); + if (err < 0) + goto out_vidh; + } + + ubi_msg(ubi, "scanning is finished"); + + /* Calculate mean erase counter */ + if (ai->ec_count) + ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count); + + err = late_analysis(ubi, ai); + if (err) + goto out_vidh; + + /* + * In case of unknown erase counter we use the mean erase counter + * value. + */ + ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) { + ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) + if (aeb->ec == UBI_UNKNOWN) + aeb->ec = ai->mean_ec; + } + + list_for_each_entry(aeb, &ai->free, u.list) { + if (aeb->ec == UBI_UNKNOWN) + aeb->ec = ai->mean_ec; + } + + list_for_each_entry(aeb, &ai->corr, u.list) + if (aeb->ec == UBI_UNKNOWN) + aeb->ec = ai->mean_ec; + + list_for_each_entry(aeb, &ai->erase, u.list) + if (aeb->ec == UBI_UNKNOWN) + aeb->ec = ai->mean_ec; + + err = self_check_ai(ubi, ai); + if (err) + goto out_vidh; + + ubi_free_vid_buf(ai->vidb); + kfree(ai->ech); + + return 0; + +out_vidh: + ubi_free_vid_buf(ai->vidb); +out_ech: + kfree(ai->ech); + return err; +} + +static struct ubi_attach_info *alloc_ai(void) +{ + struct ubi_attach_info *ai; + + ai = kzalloc(sizeof(struct ubi_attach_info), GFP_KERNEL); + if (!ai) + return ai; + + INIT_LIST_HEAD(&ai->corr); + INIT_LIST_HEAD(&ai->free); + INIT_LIST_HEAD(&ai->erase); + INIT_LIST_HEAD(&ai->alien); + INIT_LIST_HEAD(&ai->fastmap); + ai->volumes = RB_ROOT; + ai->aeb_slab_cache = kmem_cache_create("ubi_aeb_slab_cache", + sizeof(struct ubi_ainf_peb), + 0, 0, NULL); + if (!ai->aeb_slab_cache) { + kfree(ai); + ai = NULL; + } + + return ai; +} + +#ifdef CONFIG_MTD_UBI_FASTMAP + +/** + * scan_fast - try to find a fastmap and attach from it. + * @ubi: UBI device description object + * @ai: attach info object + * + * Returns 0 on success, negative return values indicate an internal + * error. + * UBI_NO_FASTMAP denotes that no fastmap was found. + * UBI_BAD_FASTMAP denotes that the found fastmap was invalid. + */ +static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info **ai) +{ + int err, pnum; + struct ubi_attach_info *scan_ai; + + err = -ENOMEM; + + scan_ai = alloc_ai(); + if (!scan_ai) + goto out; + + scan_ai->ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL); + if (!scan_ai->ech) + goto out_ai; + + scan_ai->vidb = ubi_alloc_vid_buf(ubi, GFP_KERNEL); + if (!scan_ai->vidb) + goto out_ech; + + for (pnum = 0; pnum < UBI_FM_MAX_START; pnum++) { + cond_resched(); + + dbg_gen("process PEB %d", pnum); + err = scan_peb(ubi, scan_ai, pnum, true); + if (err < 0) + goto out_vidh; + } + + ubi_free_vid_buf(scan_ai->vidb); + kfree(scan_ai->ech); + + if (scan_ai->force_full_scan) + err = UBI_NO_FASTMAP; + else + err = ubi_scan_fastmap(ubi, *ai, scan_ai); + + if (err) { + /* + * Didn't attach via fastmap, do a full scan but reuse what + * we've aready scanned. + */ + destroy_ai(*ai); + *ai = scan_ai; + } else + destroy_ai(scan_ai); + + return err; + +out_vidh: + ubi_free_vid_buf(scan_ai->vidb); +out_ech: + kfree(scan_ai->ech); +out_ai: + destroy_ai(scan_ai); +out: + return err; +} + +#endif + +/** + * ubi_attach - attach an MTD device. + * @ubi: UBI device descriptor + * @force_scan: if set to non-zero attach by scanning + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +int ubi_attach(struct ubi_device *ubi, int force_scan) +{ + int err; + struct ubi_attach_info *ai; + + ai = alloc_ai(); + if (!ai) + return -ENOMEM; + +#ifdef CONFIG_MTD_UBI_FASTMAP + /* On small flash devices we disable fastmap in any case. */ + if ((int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd) <= UBI_FM_MAX_START) { + ubi->fm_disabled = 1; + force_scan = 1; + } + + if (force_scan) + err = scan_all(ubi, ai, 0); + else { + err = scan_fast(ubi, &ai); + if (err > 0 || mtd_is_eccerr(err)) { + if (err != UBI_NO_FASTMAP) { + destroy_ai(ai); + ai = alloc_ai(); + if (!ai) + return -ENOMEM; + + err = scan_all(ubi, ai, 0); + } else { + err = scan_all(ubi, ai, UBI_FM_MAX_START); + } + } + } +#else + err = scan_all(ubi, ai, 0); +#endif + if (err) + goto out_ai; + + ubi->bad_peb_count = ai->bad_peb_count; + ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count; + ubi->corr_peb_count = ai->corr_peb_count; + ubi->max_ec = ai->max_ec; + ubi->mean_ec = ai->mean_ec; + dbg_gen("max. sequence number: %llu", ai->max_sqnum); + + err = ubi_read_volume_table(ubi, ai); + if (err) + goto out_ai; + + err = ubi_wl_init(ubi, ai); + if (err) + goto out_vtbl; + + err = ubi_eba_init(ubi, ai); + if (err) + goto out_wl; + +#ifdef CONFIG_MTD_UBI_FASTMAP + if (ubi->fm && ubi_dbg_chk_fastmap(ubi)) { + struct ubi_attach_info *scan_ai; + + scan_ai = alloc_ai(); + if (!scan_ai) { + err = -ENOMEM; + goto out_wl; + } + + err = scan_all(ubi, scan_ai, 0); + if (err) { + destroy_ai(scan_ai); + goto out_wl; + } + + err = self_check_eba(ubi, ai, scan_ai); + destroy_ai(scan_ai); + + if (err) + goto out_wl; + } +#endif + + destroy_ai(ai); + return 0; + +out_wl: + ubi_wl_close(ubi); +out_vtbl: + ubi_free_all_volumes(ubi); + vfree(ubi->vtbl); +out_ai: + destroy_ai(ai); + return err; +} + +/** + * self_check_ai - check the attaching information. + * @ubi: UBI device description object + * @ai: attaching information + * + * This function returns zero if the attaching information is all right, and a + * negative error code if not or if an error occurred. + */ +static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai) +{ + struct ubi_vid_io_buf *vidb = ai->vidb; + struct ubi_vid_hdr *vidh = ubi_get_vid_hdr(vidb); + int pnum, err, vols_found = 0; + struct rb_node *rb1, *rb2; + struct ubi_ainf_volume *av; + struct ubi_ainf_peb *aeb, *last_aeb; + uint8_t *buf; + + if (!ubi_dbg_chk_gen(ubi)) + return 0; + + /* + * At first, check that attaching information is OK. + */ + ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) { + int leb_count = 0; + + cond_resched(); + + vols_found += 1; + + if (ai->is_empty) { + ubi_err(ubi, "bad is_empty flag"); + goto bad_av; + } + + if (av->vol_id < 0 || av->highest_lnum < 0 || + av->leb_count < 0 || av->vol_type < 0 || av->used_ebs < 0 || + av->data_pad < 0 || av->last_data_size < 0) { + ubi_err(ubi, "negative values"); + goto bad_av; + } + + if (av->vol_id >= UBI_MAX_VOLUMES && + av->vol_id < UBI_INTERNAL_VOL_START) { + ubi_err(ubi, "bad vol_id"); + goto bad_av; + } + + if (av->vol_id > ai->highest_vol_id) { + ubi_err(ubi, "highest_vol_id is %d, but vol_id %d is there", + ai->highest_vol_id, av->vol_id); + goto out; + } + + if (av->vol_type != UBI_DYNAMIC_VOLUME && + av->vol_type != UBI_STATIC_VOLUME) { + ubi_err(ubi, "bad vol_type"); + goto bad_av; + } + + if (av->data_pad > ubi->leb_size / 2) { + ubi_err(ubi, "bad data_pad"); + goto bad_av; + } + + last_aeb = NULL; + ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) { + cond_resched(); + + last_aeb = aeb; + leb_count += 1; + + if (aeb->pnum < 0 || aeb->ec < 0) { + ubi_err(ubi, "negative values"); + goto bad_aeb; + } + + if (aeb->ec < ai->min_ec) { + ubi_err(ubi, "bad ai->min_ec (%d), %d found", + ai->min_ec, aeb->ec); + goto bad_aeb; + } + + if (aeb->ec > ai->max_ec) { + ubi_err(ubi, "bad ai->max_ec (%d), %d found", + ai->max_ec, aeb->ec); + goto bad_aeb; + } + + if (aeb->pnum >= ubi->peb_count) { + ubi_err(ubi, "too high PEB number %d, total PEBs %d", + aeb->pnum, ubi->peb_count); + goto bad_aeb; + } + + if (av->vol_type == UBI_STATIC_VOLUME) { + if (aeb->lnum >= av->used_ebs) { + ubi_err(ubi, "bad lnum or used_ebs"); + goto bad_aeb; + } + } else { + if (av->used_ebs != 0) { + ubi_err(ubi, "non-zero used_ebs"); + goto bad_aeb; + } + } + + if (aeb->lnum > av->highest_lnum) { + ubi_err(ubi, "incorrect highest_lnum or lnum"); + goto bad_aeb; + } + } + + if (av->leb_count != leb_count) { + ubi_err(ubi, "bad leb_count, %d objects in the tree", + leb_count); + goto bad_av; + } + + if (!last_aeb) + continue; + + aeb = last_aeb; + + if (aeb->lnum != av->highest_lnum) { + ubi_err(ubi, "bad highest_lnum"); + goto bad_aeb; + } + } + + if (vols_found != ai->vols_found) { + ubi_err(ubi, "bad ai->vols_found %d, should be %d", + ai->vols_found, vols_found); + goto out; + } + + /* Check that attaching information is correct */ + ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) { + last_aeb = NULL; + ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) { + int vol_type; + + cond_resched(); + + last_aeb = aeb; + + err = ubi_io_read_vid_hdr(ubi, aeb->pnum, vidb, 1); + if (err && err != UBI_IO_BITFLIPS) { + ubi_err(ubi, "VID header is not OK (%d)", + err); + if (err > 0) + err = -EIO; + return err; + } + + vol_type = vidh->vol_type == UBI_VID_DYNAMIC ? + UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME; + if (av->vol_type != vol_type) { + ubi_err(ubi, "bad vol_type"); + goto bad_vid_hdr; + } + + if (aeb->sqnum != be64_to_cpu(vidh->sqnum)) { + ubi_err(ubi, "bad sqnum %llu", aeb->sqnum); + goto bad_vid_hdr; + } + + if (av->vol_id != be32_to_cpu(vidh->vol_id)) { + ubi_err(ubi, "bad vol_id %d", av->vol_id); + goto bad_vid_hdr; + } + + if (av->compat != vidh->compat) { + ubi_err(ubi, "bad compat %d", vidh->compat); + goto bad_vid_hdr; + } + + if (aeb->lnum != be32_to_cpu(vidh->lnum)) { + ubi_err(ubi, "bad lnum %d", aeb->lnum); + goto bad_vid_hdr; + } + + if (av->used_ebs != be32_to_cpu(vidh->used_ebs)) { + ubi_err(ubi, "bad used_ebs %d", av->used_ebs); + goto bad_vid_hdr; + } + + if (av->data_pad != be32_to_cpu(vidh->data_pad)) { + ubi_err(ubi, "bad data_pad %d", av->data_pad); + goto bad_vid_hdr; + } + } + + if (!last_aeb) + continue; + + if (av->highest_lnum != be32_to_cpu(vidh->lnum)) { + ubi_err(ubi, "bad highest_lnum %d", av->highest_lnum); + goto bad_vid_hdr; + } + + if (av->last_data_size != be32_to_cpu(vidh->data_size)) { + ubi_err(ubi, "bad last_data_size %d", + av->last_data_size); + goto bad_vid_hdr; + } + } + + /* + * Make sure that all the physical eraseblocks are in one of the lists + * or trees. + */ + buf = kzalloc(ubi->peb_count, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + for (pnum = 0; pnum < ubi->peb_count; pnum++) { + err = ubi_io_is_bad(ubi, pnum); + if (err < 0) { + kfree(buf); + return err; + } else if (err) + buf[pnum] = 1; + } + + ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) + ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) + buf[aeb->pnum] = 1; + + list_for_each_entry(aeb, &ai->free, u.list) + buf[aeb->pnum] = 1; + + list_for_each_entry(aeb, &ai->corr, u.list) + buf[aeb->pnum] = 1; + + list_for_each_entry(aeb, &ai->erase, u.list) + buf[aeb->pnum] = 1; + + list_for_each_entry(aeb, &ai->alien, u.list) + buf[aeb->pnum] = 1; + + err = 0; + for (pnum = 0; pnum < ubi->peb_count; pnum++) + if (!buf[pnum]) { + ubi_err(ubi, "PEB %d is not referred", pnum); + err = 1; + } + + kfree(buf); + if (err) + goto out; + return 0; + +bad_aeb: + ubi_err(ubi, "bad attaching information about LEB %d", aeb->lnum); + ubi_dump_aeb(aeb, 0); + ubi_dump_av(av); + goto out; + +bad_av: + ubi_err(ubi, "bad attaching information about volume %d", av->vol_id); + ubi_dump_av(av); + goto out; + +bad_vid_hdr: + ubi_err(ubi, "bad attaching information about volume %d", av->vol_id); + ubi_dump_av(av); + ubi_dump_vid_hdr(vidh); + +out: + dump_stack(); + return -EINVAL; +} |