- 根目录:
- drivers
- mtd
- ubi
- vtbl.c
/*
* 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.
*
* 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 many data static volumes contain. This information may
* be found from the scanning data.
*
* 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, the scanning has found 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 about this corruption.
*
* 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"
#ifdef CONFIG_MTD_UBI_DEBUG
static void paranoid_vtbl_check(const struct ubi_device *ubi);
#else
#define paranoid_vtbl_check(ubi)
#endif
/* 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_unmap_leb(ubi, layout_vol, i);
if (err)
return err;
err = ubi_eba_write_leb(ubi, layout_vol, i, ubi->vtbl, 0,
ubi->vtbl_size, UBI_LONGTERM);
if (err)
return err;
}
paranoid_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_unmap_leb(ubi, layout_vol, i);
if (err)
return err;
err = ubi_eba_write_leb(ubi, layout_vol, i, ubi->vtbl, 0,
ubi->vtbl_size, UBI_LONGTERM);
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("bad CRC at record %u: %#08x, not %#08x",
i, crc, be32_to_cpu(vtbl[i].crc));
ubi_dbg_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) {
dbg_err("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) {
dbg_err("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("volumes %d and %d have the same name"
" \"%s\"", i, n, vtbl[i].name);
ubi_dbg_dump_vtbl_record(&vtbl[i], i);
ubi_dbg_dump_vtbl_record(&vtbl[n], n);
return -EINVAL;
}
}
}
return 0;
bad:
ubi_err("volume table check failed: record %d, error %d", i, err);
ubi_dbg_dump_vtbl_record(&vtbl[i], i);
return -EINVAL;
}
/**
* create_vtbl - create a copy of volume table.
* @ubi: UBI device description object
* @si: scanning 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_scan_info *si,
int copy, void *vtbl)
{
int err, tries = 0;
static struct ubi_vid_hdr *vid_hdr;
struct ubi_scan_volume *sv;
struct ubi_scan_leb *new_seb, *old_seb = NULL;
ubi_msg("create volume table (copy #%d)", copy + 1);
vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
if (!vid_hdr)
return -ENOMEM;
/*
* Check if there is a logical eraseblock which would have to contain
* this volume table copy was found during scanning. It has to be wiped
* out.
*/
sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOLUME_ID);
if (sv)
old_seb = ubi_scan_find_seb(sv, copy);
retry:
new_seb = ubi_scan_get_free_peb(ubi, si);
if (IS_ERR(new_seb)) {
err = PTR_ERR(new_seb);
goto out_free;
}
vid_hdr->vol_type = UBI_VID_DYNAMIC;
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(++si->max_sqnum);
/* The EC header is already there, write the VID header */
err = ubi_io_write_vid_hdr(ubi, new_seb->pnum, vid_hdr);
if (err)
goto write_error;
/* Write the layout volume contents */
err = ubi_io_write_data(ubi, vtbl, new_seb->pnum, 0, ubi->vtbl_size);
if (err)
goto write_error;
/*
* And add it to the scanning information. Don't delete the old
* @old_seb as it will be deleted and freed in 'ubi_scan_add_used()'.
*/
err = ubi_scan_add_used(ubi, si, new_seb->pnum, new_seb->ec,
vid_hdr, 0);
kfree(new_seb);
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_seb->u.list, &si->erase);
goto retry;
}
kfree(new_seb);
out_free:
ubi_free_vid_hdr(ubi, vid_hdr);
return err;
}
/**
* process_lvol - process the layout volume.
* @ubi: UBI device description object
* @si: scanning information
* @sv: layout volume scanning 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_scan_info *si,
struct ubi_scan_volume *sv)
{
int err;
struct rb_node *rb;
struct ubi_scan_leb *seb;
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, seb, &sv->root, u.rb) {
leb[seb->lnum] = vzalloc(ubi->vtbl_size);
if (!leb[seb->lnum]) {
err = -ENOMEM;
goto out_free;
}
err = ubi_io_read_data(ubi, leb[seb->lnum], seb->pnum, 0,
ubi->vtbl_size);
if (err == UBI_IO_BITFLIPS || err == -EBADMSG)
/*
* 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
* seb->scrub). If the data is not OK, the contents of
* the PEB will be recovered from the second copy, and
* seb->scrub will be cleared in
* 'ubi_scan_add_used()'.
*/
seb->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("volume table copy #2 is corrupted");
err = create_vtbl(ubi, si, 1, leb[0]);
if (err)
goto out_free;
ubi_msg("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("both volume tables are corrupted");
goto out_free;
}
ubi_warn("volume table copy #1 is corrupted");
err = create_vtbl(ubi, si, 0, leb[1]);
if (err)
goto out_free;
ubi_msg("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
* @si: scanning 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_scan_info *si)
{
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, si, 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
* @si: 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_scan_info *si,
const struct ubi_vtbl_record *vtbl)
{
int i, reserved_pebs = 0;
struct ubi_scan_volume *sv;
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("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 */
sv = ubi_scan_find_sv(si, i);
if (!sv) {
/*
* 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 (sv->leb_count != sv->used_ebs) {
/*
* We found a static volume which misses several
* eraseblocks. Treat it as corrupted.
*/
ubi_warn("static volume %d misses %d LEBs - corrupted",
sv->vol_id, sv->used_ebs - sv->leb_count);
vol->corrupted = 1;
continue;
}
vol->used_ebs = sv->used_ebs;
vol->used_bytes =
(long long)(vol->used_ebs - 1) * vol->usable_leb_size;
vol->used_bytes += sv->last_data_size;
vol->last_eb_bytes = sv->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 = 1;
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("not enough PEBs, required %d, available %d",
reserved_pebs, ubi->avail_pebs);
if (ubi->corr_peb_count)
ubi_err("%d PEBs are corrupted and not used",
ubi->corr_peb_count);
}
ubi->rsvd_pebs += reserved_pebs;
ubi->avail_pebs -= reserved_pebs;
return 0;
}
/**
* check_sv - check volume scanning information.
* @vol: UBI volume description object
* @sv: volume scanning information
*
* This function returns zero if the volume scanning information is consistent
* to the data read from the volume tabla, and %-EINVAL if not.
*/
static int check_sv(const struct ubi_volume *vol,
const struct ubi_scan_volume *sv)
{
int err;
if (sv->highest_lnum >= vol->reserved_pebs) {
err = 1;
goto bad;
}
if (sv->leb_count > vol->reserved_pebs) {
err = 2;
goto bad;
}
if (sv->vol_type != vol->vol_type) {
err = 3;
goto bad;
}
if (sv->used_ebs > vol->reserved_pebs) {
err = 4;
goto bad;
}
if (sv->data_pad != vol->data_pad) {
err = 5;
goto bad;
}
return 0;
bad:
ubi_err("bad scanning information, error %d", err);
ubi_dbg_dump_sv(sv);
ubi_dbg_dump_vol_info(vol);
return -EINVAL;
}
/**
* check_scanning_info - check that scanning information.
* @ubi: UBI device description object
* @si: scanning information
*
* Even though we protect on-flash data by CRC checksums, we still don't trust
* the media. This function ensures that scanning information is consistent to
* the information read from the volume table. Returns zero if the scanning
* information is OK and %-EINVAL if it is not.
*/
static int check_scanning_info(const struct ubi_device *ubi,
struct ubi_scan_info *si)
{
int err, i;
struct ubi_scan_volume *sv;
struct ubi_volume *vol;
if (si->vols_found > UBI_INT_VOL_COUNT + ubi->vtbl_slots) {
ubi_err("scanning found %d volumes, maximum is %d + %d",
si->vols_found, UBI_INT_VOL_COUNT, ubi->vtbl_slots);
return -EINVAL;
}
if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT &&
si->highest_vol_id < UBI_INTERNAL_VOL_START) {
ubi_err("too large volume ID %d found by scanning",
si->highest_vol_id);
return -EINVAL;
}
for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
cond_resched();
sv = ubi_scan_find_sv(si, i);
vol = ubi->volumes[i];
if (!vol) {
if (sv)
ubi_scan_rm_volume(si, sv);
continue;
}
if (vol->reserved_pebs == 0) {
ubi_assert(i < ubi->vtbl_slots);
if (!sv)
continue;
/*
* During scanning 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("finish volume %d removal", sv->vol_id);
ubi_scan_rm_volume(si, sv);
} else if (sv) {
err = check_sv(vol, sv);
if (err)
return err;
}
}
return 0;
}
/**
* ubi_read_volume_table - read the volume table.
* @ubi: UBI device description object
* @si: scanning 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_scan_info *si)
{
int i, err;
struct ubi_scan_volume *sv;
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);
sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOLUME_ID);
if (!sv) {
/*
* 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 (si->is_empty) {
ubi->vtbl = create_empty_lvol(ubi, si);
if (IS_ERR(ubi->vtbl))
return PTR_ERR(ubi->vtbl);
} else {
ubi_err("the layout volume was not found");
return -EINVAL;
}
} else {
if (sv->leb_count > UBI_LAYOUT_VOLUME_EBS) {
/* This must not happen with proper UBI images */
dbg_err("too many LEBs (%d) in layout volume",
sv->leb_count);
return -EINVAL;
}
ubi->vtbl = process_lvol(ubi, si, sv);
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, si, ubi->vtbl);
if (err)
goto out_free;
/*
* Make sure that the scanning information is consistent to the
* information stored in the volume table.
*/
err = check_scanning_info(ubi, si);
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;
}
#ifdef CONFIG_MTD_UBI_DEBUG
/**
* paranoid_vtbl_check - check volume table.
* @ubi: UBI device description object
*/
static void paranoid_vtbl_check(const struct ubi_device *ubi)
{
if (!(ubi_chk_flags & UBI_CHK_GEN))
return;
if (vtbl_check(ubi, ubi->vtbl)) {
ubi_err("paranoid check failed");
BUG();
}
}
#endif /* CONFIG_MTD_UBI_DEBUG */