diff options
Diffstat (limited to 'drivers/mtd/ubi/vtbl.c')
| -rw-r--r-- | drivers/mtd/ubi/vtbl.c | 864 |
1 files changed, 864 insertions, 0 deletions
diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c new file mode 100644 index 000000000..68c9c5ea6 --- /dev/null +++ b/drivers/mtd/ubi/vtbl.c @@ -0,0 +1,864 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * Copyright (c) Nokia Corporation, 2006, 2007 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file includes volume table manipulation code. The volume table is an + * on-flash table containing volume meta-data like name, number of reserved + * physical eraseblocks, type, etc. The volume table is stored in the so-called + * "layout volume". + * + * The layout volume is an internal volume which is organized as follows. It + * consists of two logical eraseblocks - LEB 0 and LEB 1. Each logical + * eraseblock stores one volume table copy, i.e. LEB 0 and LEB 1 duplicate each + * other. This redundancy guarantees robustness to unclean reboots. The volume + * table is basically an array of volume table records. Each record contains + * full information about the volume and protected by a CRC checksum. Note, + * nowadays we use the atomic LEB change operation when updating the volume + * table, so we do not really need 2 LEBs anymore, but we preserve the older + * design for the backward compatibility reasons. + * + * When the volume table is changed, it is first changed in RAM. Then LEB 0 is + * erased, and the updated volume table is written back to LEB 0. Then same for + * LEB 1. This scheme guarantees recoverability from unclean reboots. + * + * In this UBI implementation the on-flash volume table does not contain any + * information about how much data static volumes contain. + * + * But it would still be beneficial to store this information in the volume + * table. For example, suppose we have a static volume X, and all its physical + * eraseblocks became bad for some reasons. Suppose we are attaching the + * corresponding MTD device, for some reason we find no logical eraseblocks + * corresponding to the volume X. According to the volume table volume X does + * exist. So we don't know whether it is just empty or all its physical + * eraseblocks went bad. So we cannot alarm the user properly. + * + * The volume table also stores so-called "update marker", which is used for + * volume updates. Before updating the volume, the update marker is set, and + * after the update operation is finished, the update marker is cleared. So if + * the update operation was interrupted (e.g. by an unclean reboot) - the + * update marker is still there and we know that the volume's contents is + * damaged. + */ + +#include <linux/crc32.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <asm/div64.h> +#include "ubi.h" + +static void self_vtbl_check(const struct ubi_device *ubi); + +/* Empty volume table record */ +static struct ubi_vtbl_record empty_vtbl_record; + +/** + * ubi_change_vtbl_record - change volume table record. + * @ubi: UBI device description object + * @idx: table index to change + * @vtbl_rec: new volume table record + * + * This function changes volume table record @idx. If @vtbl_rec is %NULL, empty + * volume table record is written. The caller does not have to calculate CRC of + * the record as it is done by this function. Returns zero in case of success + * and a negative error code in case of failure. + */ +int ubi_change_vtbl_record(struct ubi_device *ubi, int idx, + struct ubi_vtbl_record *vtbl_rec) +{ + int i, err; + uint32_t crc; + struct ubi_volume *layout_vol; + + ubi_assert(idx >= 0 && idx < ubi->vtbl_slots); + layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)]; + + if (!vtbl_rec) + vtbl_rec = &empty_vtbl_record; + else { + crc = crc32(UBI_CRC32_INIT, vtbl_rec, UBI_VTBL_RECORD_SIZE_CRC); + vtbl_rec->crc = cpu_to_be32(crc); + } + + memcpy(&ubi->vtbl[idx], vtbl_rec, sizeof(struct ubi_vtbl_record)); + for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { + err = ubi_eba_atomic_leb_change(ubi, layout_vol, i, ubi->vtbl, + ubi->vtbl_size); + if (err) + return err; + } + + self_vtbl_check(ubi); + return 0; +} + +/** + * ubi_vtbl_rename_volumes - rename UBI volumes in the volume table. + * @ubi: UBI device description object + * @rename_list: list of &struct ubi_rename_entry objects + * + * This function re-names multiple volumes specified in @req in the volume + * table. Returns zero in case of success and a negative error code in case of + * failure. + */ +int ubi_vtbl_rename_volumes(struct ubi_device *ubi, + struct list_head *rename_list) +{ + int i, err; + struct ubi_rename_entry *re; + struct ubi_volume *layout_vol; + + list_for_each_entry(re, rename_list, list) { + uint32_t crc; + struct ubi_volume *vol = re->desc->vol; + struct ubi_vtbl_record *vtbl_rec = &ubi->vtbl[vol->vol_id]; + + if (re->remove) { + memcpy(vtbl_rec, &empty_vtbl_record, + sizeof(struct ubi_vtbl_record)); + continue; + } + + vtbl_rec->name_len = cpu_to_be16(re->new_name_len); + memcpy(vtbl_rec->name, re->new_name, re->new_name_len); + memset(vtbl_rec->name + re->new_name_len, 0, + UBI_VOL_NAME_MAX + 1 - re->new_name_len); + crc = crc32(UBI_CRC32_INIT, vtbl_rec, + UBI_VTBL_RECORD_SIZE_CRC); + vtbl_rec->crc = cpu_to_be32(crc); + } + + layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)]; + for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { + err = ubi_eba_atomic_leb_change(ubi, layout_vol, i, ubi->vtbl, + ubi->vtbl_size); + if (err) + return err; + } + + return 0; +} + +/** + * vtbl_check - check if volume table is not corrupted and sensible. + * @ubi: UBI device description object + * @vtbl: volume table + * + * This function returns zero if @vtbl is all right, %1 if CRC is incorrect, + * and %-EINVAL if it contains inconsistent data. + */ +static int vtbl_check(const struct ubi_device *ubi, + const struct ubi_vtbl_record *vtbl) +{ + int i, n, reserved_pebs, alignment, data_pad, vol_type, name_len; + int upd_marker, err; + uint32_t crc; + const char *name; + + for (i = 0; i < ubi->vtbl_slots; i++) { + cond_resched(); + + reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs); + alignment = be32_to_cpu(vtbl[i].alignment); + data_pad = be32_to_cpu(vtbl[i].data_pad); + upd_marker = vtbl[i].upd_marker; + vol_type = vtbl[i].vol_type; + name_len = be16_to_cpu(vtbl[i].name_len); + name = &vtbl[i].name[0]; + + crc = crc32(UBI_CRC32_INIT, &vtbl[i], UBI_VTBL_RECORD_SIZE_CRC); + if (be32_to_cpu(vtbl[i].crc) != crc) { + ubi_err(ubi, "bad CRC at record %u: %#08x, not %#08x", + i, crc, be32_to_cpu(vtbl[i].crc)); + ubi_dump_vtbl_record(&vtbl[i], i); + return 1; + } + + if (reserved_pebs == 0) { + if (memcmp(&vtbl[i], &empty_vtbl_record, + UBI_VTBL_RECORD_SIZE)) { + err = 2; + goto bad; + } + continue; + } + + if (reserved_pebs < 0 || alignment < 0 || data_pad < 0 || + name_len < 0) { + err = 3; + goto bad; + } + + if (alignment > ubi->leb_size || alignment == 0) { + err = 4; + goto bad; + } + + n = alignment & (ubi->min_io_size - 1); + if (alignment != 1 && n) { + err = 5; + goto bad; + } + + n = ubi->leb_size % alignment; + if (data_pad != n) { + ubi_err(ubi, "bad data_pad, has to be %d", n); + err = 6; + goto bad; + } + + if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) { + err = 7; + goto bad; + } + + if (upd_marker != 0 && upd_marker != 1) { + err = 8; + goto bad; + } + + if (reserved_pebs > ubi->good_peb_count) { + ubi_err(ubi, "too large reserved_pebs %d, good PEBs %d", + reserved_pebs, ubi->good_peb_count); + err = 9; + goto bad; + } + + if (name_len > UBI_VOL_NAME_MAX) { + err = 10; + goto bad; + } + + if (name[0] == '\0') { + err = 11; + goto bad; + } + + if (name_len != strnlen(name, name_len + 1)) { + err = 12; + goto bad; + } + } + + /* Checks that all names are unique */ + for (i = 0; i < ubi->vtbl_slots - 1; i++) { + for (n = i + 1; n < ubi->vtbl_slots; n++) { + int len1 = be16_to_cpu(vtbl[i].name_len); + int len2 = be16_to_cpu(vtbl[n].name_len); + + if (len1 > 0 && len1 == len2 && + !strncmp(vtbl[i].name, vtbl[n].name, len1)) { + ubi_err(ubi, "volumes %d and %d have the same name \"%s\"", + i, n, vtbl[i].name); + ubi_dump_vtbl_record(&vtbl[i], i); + ubi_dump_vtbl_record(&vtbl[n], n); + return -EINVAL; + } + } + } + + return 0; + +bad: + ubi_err(ubi, "volume table check failed: record %d, error %d", i, err); + ubi_dump_vtbl_record(&vtbl[i], i); + return -EINVAL; +} + +/** + * create_vtbl - create a copy of volume table. + * @ubi: UBI device description object + * @ai: attaching information + * @copy: number of the volume table copy + * @vtbl: contents of the volume table + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int create_vtbl(struct ubi_device *ubi, struct ubi_attach_info *ai, + int copy, void *vtbl) +{ + int err, tries = 0; + struct ubi_vid_hdr *vid_hdr; + struct ubi_ainf_peb *new_aeb; + + dbg_gen("create volume table (copy #%d)", copy + 1); + + vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL); + if (!vid_hdr) + return -ENOMEM; + +retry: + new_aeb = ubi_early_get_peb(ubi, ai); + if (IS_ERR(new_aeb)) { + err = PTR_ERR(new_aeb); + goto out_free; + } + + vid_hdr->vol_type = UBI_LAYOUT_VOLUME_TYPE; + vid_hdr->vol_id = cpu_to_be32(UBI_LAYOUT_VOLUME_ID); + vid_hdr->compat = UBI_LAYOUT_VOLUME_COMPAT; + vid_hdr->data_size = vid_hdr->used_ebs = + vid_hdr->data_pad = cpu_to_be32(0); + vid_hdr->lnum = cpu_to_be32(copy); + vid_hdr->sqnum = cpu_to_be64(++ai->max_sqnum); + + /* The EC header is already there, write the VID header */ + err = ubi_io_write_vid_hdr(ubi, new_aeb->pnum, vid_hdr); + if (err) + goto write_error; + + /* Write the layout volume contents */ + err = ubi_io_write_data(ubi, vtbl, new_aeb->pnum, 0, ubi->vtbl_size); + if (err) + goto write_error; + + /* + * And add it to the attaching information. Don't delete the old version + * of this LEB as it will be deleted and freed in 'ubi_add_to_av()'. + */ + err = ubi_add_to_av(ubi, ai, new_aeb->pnum, new_aeb->ec, vid_hdr, 0); + kmem_cache_free(ai->aeb_slab_cache, new_aeb); + ubi_free_vid_hdr(ubi, vid_hdr); + return err; + +write_error: + if (err == -EIO && ++tries <= 5) { + /* + * Probably this physical eraseblock went bad, try to pick + * another one. + */ + list_add(&new_aeb->u.list, &ai->erase); + goto retry; + } + kmem_cache_free(ai->aeb_slab_cache, new_aeb); +out_free: + ubi_free_vid_hdr(ubi, vid_hdr); + return err; + +} + +/** + * process_lvol - process the layout volume. + * @ubi: UBI device description object + * @ai: attaching information + * @av: layout volume attaching information + * + * This function is responsible for reading the layout volume, ensuring it is + * not corrupted, and recovering from corruptions if needed. Returns volume + * table in case of success and a negative error code in case of failure. + */ +static struct ubi_vtbl_record *process_lvol(struct ubi_device *ubi, + struct ubi_attach_info *ai, + struct ubi_ainf_volume *av) +{ + int err; + struct rb_node *rb; + struct ubi_ainf_peb *aeb; + struct ubi_vtbl_record *leb[UBI_LAYOUT_VOLUME_EBS] = { NULL, NULL }; + int leb_corrupted[UBI_LAYOUT_VOLUME_EBS] = {1, 1}; + + /* + * UBI goes through the following steps when it changes the layout + * volume: + * a. erase LEB 0; + * b. write new data to LEB 0; + * c. erase LEB 1; + * d. write new data to LEB 1. + * + * Before the change, both LEBs contain the same data. + * + * Due to unclean reboots, the contents of LEB 0 may be lost, but there + * should LEB 1. So it is OK if LEB 0 is corrupted while LEB 1 is not. + * Similarly, LEB 1 may be lost, but there should be LEB 0. And + * finally, unclean reboots may result in a situation when neither LEB + * 0 nor LEB 1 are corrupted, but they are different. In this case, LEB + * 0 contains more recent information. + * + * So the plan is to first check LEB 0. Then + * a. if LEB 0 is OK, it must be containing the most recent data; then + * we compare it with LEB 1, and if they are different, we copy LEB + * 0 to LEB 1; + * b. if LEB 0 is corrupted, but LEB 1 has to be OK, and we copy LEB 1 + * to LEB 0. + */ + + dbg_gen("check layout volume"); + + /* Read both LEB 0 and LEB 1 into memory */ + ubi_rb_for_each_entry(rb, aeb, &av->root, u.rb) { + leb[aeb->lnum] = vzalloc(ubi->vtbl_size); + if (!leb[aeb->lnum]) { + err = -ENOMEM; + goto out_free; + } + + err = ubi_io_read_data(ubi, leb[aeb->lnum], aeb->pnum, 0, + ubi->vtbl_size); + if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) + /* + * Scrub the PEB later. Note, -EBADMSG indicates an + * uncorrectable ECC error, but we have our own CRC and + * the data will be checked later. If the data is OK, + * the PEB will be scrubbed (because we set + * aeb->scrub). If the data is not OK, the contents of + * the PEB will be recovered from the second copy, and + * aeb->scrub will be cleared in + * 'ubi_add_to_av()'. + */ + aeb->scrub = 1; + else if (err) + goto out_free; + } + + err = -EINVAL; + if (leb[0]) { + leb_corrupted[0] = vtbl_check(ubi, leb[0]); + if (leb_corrupted[0] < 0) + goto out_free; + } + + if (!leb_corrupted[0]) { + /* LEB 0 is OK */ + if (leb[1]) + leb_corrupted[1] = memcmp(leb[0], leb[1], + ubi->vtbl_size); + if (leb_corrupted[1]) { + ubi_warn(ubi, "volume table copy #2 is corrupted"); + err = create_vtbl(ubi, ai, 1, leb[0]); + if (err) + goto out_free; + ubi_msg(ubi, "volume table was restored"); + } + + /* Both LEB 1 and LEB 2 are OK and consistent */ + vfree(leb[1]); + return leb[0]; + } else { + /* LEB 0 is corrupted or does not exist */ + if (leb[1]) { + leb_corrupted[1] = vtbl_check(ubi, leb[1]); + if (leb_corrupted[1] < 0) + goto out_free; + } + if (leb_corrupted[1]) { + /* Both LEB 0 and LEB 1 are corrupted */ + ubi_err(ubi, "both volume tables are corrupted"); + goto out_free; + } + + ubi_warn(ubi, "volume table copy #1 is corrupted"); + err = create_vtbl(ubi, ai, 0, leb[1]); + if (err) + goto out_free; + ubi_msg(ubi, "volume table was restored"); + + vfree(leb[0]); + return leb[1]; + } + +out_free: + vfree(leb[0]); + vfree(leb[1]); + return ERR_PTR(err); +} + +/** + * create_empty_lvol - create empty layout volume. + * @ubi: UBI device description object + * @ai: attaching information + * + * This function returns volume table contents in case of success and a + * negative error code in case of failure. + */ +static struct ubi_vtbl_record *create_empty_lvol(struct ubi_device *ubi, + struct ubi_attach_info *ai) +{ + int i; + struct ubi_vtbl_record *vtbl; + + vtbl = vzalloc(ubi->vtbl_size); + if (!vtbl) + return ERR_PTR(-ENOMEM); + + for (i = 0; i < ubi->vtbl_slots; i++) + memcpy(&vtbl[i], &empty_vtbl_record, UBI_VTBL_RECORD_SIZE); + + for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { + int err; + + err = create_vtbl(ubi, ai, i, vtbl); + if (err) { + vfree(vtbl); + return ERR_PTR(err); + } + } + + return vtbl; +} + +/** + * init_volumes - initialize volume information for existing volumes. + * @ubi: UBI device description object + * @ai: scanning information + * @vtbl: volume table + * + * This function allocates volume description objects for existing volumes. + * Returns zero in case of success and a negative error code in case of + * failure. + */ +static int init_volumes(struct ubi_device *ubi, + const struct ubi_attach_info *ai, + const struct ubi_vtbl_record *vtbl) +{ + int i, reserved_pebs = 0; + struct ubi_ainf_volume *av; + struct ubi_volume *vol; + + for (i = 0; i < ubi->vtbl_slots; i++) { + cond_resched(); + + if (be32_to_cpu(vtbl[i].reserved_pebs) == 0) + continue; /* Empty record */ + + vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); + if (!vol) + return -ENOMEM; + + vol->reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs); + vol->alignment = be32_to_cpu(vtbl[i].alignment); + vol->data_pad = be32_to_cpu(vtbl[i].data_pad); + vol->upd_marker = vtbl[i].upd_marker; + vol->vol_type = vtbl[i].vol_type == UBI_VID_DYNAMIC ? + UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME; + vol->name_len = be16_to_cpu(vtbl[i].name_len); + vol->usable_leb_size = ubi->leb_size - vol->data_pad; + memcpy(vol->name, vtbl[i].name, vol->name_len); + vol->name[vol->name_len] = '\0'; + vol->vol_id = i; + + if (vtbl[i].flags & UBI_VTBL_AUTORESIZE_FLG) { + /* Auto re-size flag may be set only for one volume */ + if (ubi->autoresize_vol_id != -1) { + ubi_err(ubi, "more than one auto-resize volume (%d and %d)", + ubi->autoresize_vol_id, i); + kfree(vol); + return -EINVAL; + } + + ubi->autoresize_vol_id = i; + } + + ubi_assert(!ubi->volumes[i]); + ubi->volumes[i] = vol; + ubi->vol_count += 1; + vol->ubi = ubi; + reserved_pebs += vol->reserved_pebs; + + /* + * In case of dynamic volume UBI knows nothing about how many + * data is stored there. So assume the whole volume is used. + */ + if (vol->vol_type == UBI_DYNAMIC_VOLUME) { + vol->used_ebs = vol->reserved_pebs; + vol->last_eb_bytes = vol->usable_leb_size; + vol->used_bytes = + (long long)vol->used_ebs * vol->usable_leb_size; + continue; + } + + /* Static volumes only */ + av = ubi_find_av(ai, i); + if (!av || !av->leb_count) { + /* + * No eraseblocks belonging to this volume found. We + * don't actually know whether this static volume is + * completely corrupted or just contains no data. And + * we cannot know this as long as data size is not + * stored on flash. So we just assume the volume is + * empty. FIXME: this should be handled. + */ + continue; + } + + if (av->leb_count != av->used_ebs) { + /* + * We found a static volume which misses several + * eraseblocks. Treat it as corrupted. + */ + ubi_warn(ubi, "static volume %d misses %d LEBs - corrupted", + av->vol_id, av->used_ebs - av->leb_count); + vol->corrupted = 1; + continue; + } + + vol->used_ebs = av->used_ebs; + vol->used_bytes = + (long long)(vol->used_ebs - 1) * vol->usable_leb_size; + vol->used_bytes += av->last_data_size; + vol->last_eb_bytes = av->last_data_size; + } + + /* And add the layout volume */ + vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); + if (!vol) + return -ENOMEM; + + vol->reserved_pebs = UBI_LAYOUT_VOLUME_EBS; + vol->alignment = UBI_LAYOUT_VOLUME_ALIGN; + vol->vol_type = UBI_DYNAMIC_VOLUME; + vol->name_len = sizeof(UBI_LAYOUT_VOLUME_NAME) - 1; + memcpy(vol->name, UBI_LAYOUT_VOLUME_NAME, vol->name_len + 1); + vol->usable_leb_size = ubi->leb_size; + vol->used_ebs = vol->reserved_pebs; + vol->last_eb_bytes = vol->reserved_pebs; + vol->used_bytes = + (long long)vol->used_ebs * (ubi->leb_size - vol->data_pad); + vol->vol_id = UBI_LAYOUT_VOLUME_ID; + vol->ref_count = 1; + + ubi_assert(!ubi->volumes[i]); + ubi->volumes[vol_id2idx(ubi, vol->vol_id)] = vol; + reserved_pebs += vol->reserved_pebs; + ubi->vol_count += 1; + vol->ubi = ubi; + + if (reserved_pebs > ubi->avail_pebs) { + ubi_err(ubi, "not enough PEBs, required %d, available %d", + reserved_pebs, ubi->avail_pebs); + if (ubi->corr_peb_count) + ubi_err(ubi, "%d PEBs are corrupted and not used", + ubi->corr_peb_count); + } + ubi->rsvd_pebs += reserved_pebs; + ubi->avail_pebs -= reserved_pebs; + + return 0; +} + +/** + * check_av - check volume attaching information. + * @vol: UBI volume description object + * @av: volume attaching information + * + * This function returns zero if the volume attaching information is consistent + * to the data read from the volume tabla, and %-EINVAL if not. + */ +static int check_av(const struct ubi_volume *vol, + const struct ubi_ainf_volume *av) +{ + int err; + + if (av->highest_lnum >= vol->reserved_pebs) { + err = 1; + goto bad; + } + if (av->leb_count > vol->reserved_pebs) { + err = 2; + goto bad; + } + if (av->vol_type != vol->vol_type) { + err = 3; + goto bad; + } + if (av->used_ebs > vol->reserved_pebs) { + err = 4; + goto bad; + } + if (av->data_pad != vol->data_pad) { + err = 5; + goto bad; + } + return 0; + +bad: + ubi_err(vol->ubi, "bad attaching information, error %d", err); + ubi_dump_av(av); + ubi_dump_vol_info(vol); + return -EINVAL; +} + +/** + * check_attaching_info - check that attaching information. + * @ubi: UBI device description object + * @ai: attaching information + * + * Even though we protect on-flash data by CRC checksums, we still don't trust + * the media. This function ensures that attaching information is consistent to + * the information read from the volume table. Returns zero if the attaching + * information is OK and %-EINVAL if it is not. + */ +static int check_attaching_info(const struct ubi_device *ubi, + struct ubi_attach_info *ai) +{ + int err, i; + struct ubi_ainf_volume *av; + struct ubi_volume *vol; + + if (ai->vols_found > UBI_INT_VOL_COUNT + ubi->vtbl_slots) { + ubi_err(ubi, "found %d volumes while attaching, maximum is %d + %d", + ai->vols_found, UBI_INT_VOL_COUNT, ubi->vtbl_slots); + return -EINVAL; + } + + if (ai->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT && + ai->highest_vol_id < UBI_INTERNAL_VOL_START) { + ubi_err(ubi, "too large volume ID %d found", + ai->highest_vol_id); + return -EINVAL; + } + + for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) { + cond_resched(); + + av = ubi_find_av(ai, i); + vol = ubi->volumes[i]; + if (!vol) { + if (av) + ubi_remove_av(ai, av); + continue; + } + + if (vol->reserved_pebs == 0) { + ubi_assert(i < ubi->vtbl_slots); + + if (!av) + continue; + + /* + * During attaching we found a volume which does not + * exist according to the information in the volume + * table. This must have happened due to an unclean + * reboot while the volume was being removed. Discard + * these eraseblocks. + */ + ubi_msg(ubi, "finish volume %d removal", av->vol_id); + ubi_remove_av(ai, av); + } else if (av) { + err = check_av(vol, av); + if (err) + return err; + } + } + + return 0; +} + +/** + * ubi_read_volume_table - read the volume table. + * @ubi: UBI device description object + * @ai: attaching information + * + * This function reads volume table, checks it, recover from errors if needed, + * or creates it if needed. Returns zero in case of success and a negative + * error code in case of failure. + */ +int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai) +{ + int i, err; + struct ubi_ainf_volume *av; + + empty_vtbl_record.crc = cpu_to_be32(0xf116c36b); + + /* + * The number of supported volumes is limited by the eraseblock size + * and by the UBI_MAX_VOLUMES constant. + */ + ubi->vtbl_slots = ubi->leb_size / UBI_VTBL_RECORD_SIZE; + if (ubi->vtbl_slots > UBI_MAX_VOLUMES) + ubi->vtbl_slots = UBI_MAX_VOLUMES; + + ubi->vtbl_size = ubi->vtbl_slots * UBI_VTBL_RECORD_SIZE; + ubi->vtbl_size = ALIGN(ubi->vtbl_size, ubi->min_io_size); + + av = ubi_find_av(ai, UBI_LAYOUT_VOLUME_ID); + if (!av) { + /* + * No logical eraseblocks belonging to the layout volume were + * found. This could mean that the flash is just empty. In + * this case we create empty layout volume. + * + * But if flash is not empty this must be a corruption or the + * MTD device just contains garbage. + */ + if (ai->is_empty) { + ubi->vtbl = create_empty_lvol(ubi, ai); + if (IS_ERR(ubi->vtbl)) + return PTR_ERR(ubi->vtbl); + } else { + ubi_err(ubi, "the layout volume was not found"); + return -EINVAL; + } + } else { + if (av->leb_count > UBI_LAYOUT_VOLUME_EBS) { + /* This must not happen with proper UBI images */ + ubi_err(ubi, "too many LEBs (%d) in layout volume", + av->leb_count); + return -EINVAL; + } + + ubi->vtbl = process_lvol(ubi, ai, av); + if (IS_ERR(ubi->vtbl)) + return PTR_ERR(ubi->vtbl); + } + + ubi->avail_pebs = ubi->good_peb_count - ubi->corr_peb_count; + + /* + * The layout volume is OK, initialize the corresponding in-RAM data + * structures. + */ + err = init_volumes(ubi, ai, ubi->vtbl); + if (err) + goto out_free; + + /* + * Make sure that the attaching information is consistent to the + * information stored in the volume table. + */ + err = check_attaching_info(ubi, ai); + if (err) + goto out_free; + + return 0; + +out_free: + vfree(ubi->vtbl); + for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) { + kfree(ubi->volumes[i]); + ubi->volumes[i] = NULL; + } + return err; +} + +/** + * self_vtbl_check - check volume table. + * @ubi: UBI device description object + */ +static void self_vtbl_check(const struct ubi_device *ubi) +{ + if (!ubi_dbg_chk_gen(ubi)) + return; + + if (vtbl_check(ubi, ubi->vtbl)) { + ubi_err(ubi, "self-check failed"); + BUG(); + } +} |