/*
Trivial Database 2: free list/block handling
Copyright (C) Rusty Russell 2010
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see .
*/
#include "private.h"
#include
#include
/* We keep an ordered array of offsets. */
static bool append(tdb_off_t **arr, size_t *num, tdb_off_t off)
{
tdb_off_t *new = realloc(*arr, (*num + 1) * sizeof(tdb_off_t));
if (!new)
return false;
new[(*num)++] = off;
*arr = new;
return true;
}
static bool check_header(struct tdb_context *tdb)
{
uint64_t hash_test;
struct tdb_header hdr;
if (tdb_read_convert(tdb, 0, &hdr, sizeof(hdr)) == -1)
return false;
/* magic food should not be converted, so convert back. */
tdb_convert(tdb, hdr.magic_food, sizeof(hdr.magic_food));
hash_test = TDB_HASH_MAGIC;
hash_test = tdb_hash(tdb, &hash_test, sizeof(hash_test));
if (hdr.hash_test != hash_test) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"check: hash test %llu should be %llu\n",
(long long)hdr.hash_test,
(long long)hash_test);
return false;
}
if (strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"check: bad magic '%.*s'\n",
(unsigned)sizeof(hdr.magic_food), hdr.magic_food);
return false;
}
/* Don't check reserved: they *can* be used later. */
return true;
}
static bool check_hash_tree(struct tdb_context *tdb,
tdb_off_t off, unsigned int group_bits,
uint64_t hprefix,
unsigned hprefix_bits,
tdb_off_t used[],
size_t num_used,
size_t *num_found);
static bool check_hash_record(struct tdb_context *tdb,
tdb_off_t off,
uint64_t hprefix,
unsigned hprefix_bits,
tdb_off_t used[],
size_t num_used,
size_t *num_found)
{
struct tdb_used_record rec;
if (tdb_read_convert(tdb, off, &rec, sizeof(rec)) == -1)
return false;
if (rec_data_length(&rec)
!= sizeof(tdb_off_t) << TDB_SUBLEVEL_HASH_BITS) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: Bad hash table length %llu vs %llu\n",
(long long)rec_data_length(&rec),
(long long)sizeof(tdb_off_t)<log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: Bad hash table key length %llu\n",
(long long)rec_key_length(&rec));
return false;
}
if (rec_hash(&rec) != 0) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: Bad hash table hash value %llu\n",
(long long)rec_hash(&rec));
return false;
}
off += sizeof(rec);
return check_hash_tree(tdb, off,
TDB_SUBLEVEL_HASH_BITS-TDB_HASH_GROUP_BITS,
hprefix, hprefix_bits,
used, num_used, num_found);
}
static int off_cmp(const tdb_off_t *a, const tdb_off_t *b)
{
/* Can overflow an int. */
return *a > *b ? 1
: *a < *b ? -1
: 0;
}
static uint64_t get_bits(uint64_t h, unsigned num, unsigned *used)
{
*used += num;
return (h >> (64 - *used)) & ((1U << num) - 1);
}
static bool check_hash_tree(struct tdb_context *tdb,
tdb_off_t off, unsigned int group_bits,
uint64_t hprefix,
unsigned hprefix_bits,
tdb_off_t used[],
size_t num_used,
size_t *num_found)
{
unsigned int g, b;
const tdb_off_t *hash;
struct tdb_used_record rec;
hash = tdb_access_read(tdb, off,
sizeof(tdb_off_t)
<< (group_bits + TDB_HASH_GROUP_BITS),
true);
if (!hash)
return false;
for (g = 0; g < (1 << group_bits); g++) {
const tdb_off_t *group = hash + (g << TDB_HASH_GROUP_BITS);
for (b = 0; b < (1 << TDB_HASH_GROUP_BITS); b++) {
unsigned int bucket, i, used_bits;
uint64_t h;
tdb_off_t *p;
if (group[b] == 0)
continue;
off = group[b] & TDB_OFF_MASK;
p = asearch(&off, used, num_used, off_cmp);
if (!p) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: Invalid offset %llu "
"in hash\n",
(long long)off);
goto fail;
}
/* Mark it invalid. */
*p ^= 1;
(*num_found)++;
if (is_subhash(group[b])) {
uint64_t subprefix;
subprefix = (hprefix
<< (group_bits + TDB_HASH_GROUP_BITS))
+ g * (1 << TDB_HASH_GROUP_BITS) + b;
if (!check_hash_record(tdb,
group[b] & TDB_OFF_MASK,
subprefix,
hprefix_bits
+ group_bits
+ TDB_HASH_GROUP_BITS,
used, num_used, num_found))
goto fail;
continue;
}
/* A normal entry */
/* Does it belong here at all? */
h = hash_record(tdb, off);
used_bits = 0;
if (get_bits(h, hprefix_bits, &used_bits) != hprefix
&& hprefix_bits) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"check: bad hash placement"
" 0x%llx vs 0x%llx\n",
(long long)h, (long long)hprefix);
goto fail;
}
/* Does it belong in this group? */
if (get_bits(h, group_bits, &used_bits) != g) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"check: bad group %llu vs %u\n",
(long long)h, g);
goto fail;
}
/* Are bucket bits correct? */
bucket = group[b] & TDB_OFF_HASH_GROUP_MASK;
if (get_bits(h, TDB_HASH_GROUP_BITS, &used_bits)
!= bucket) {
used_bits -= TDB_HASH_GROUP_BITS;
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"check: bad bucket %u vs %u\n",
(unsigned)get_bits(h,
TDB_HASH_GROUP_BITS,
&used_bits),
bucket);
goto fail;
}
/* There must not be any zero entries between
* the bucket it belongs in and this one! */
for (i = bucket;
i != b;
i = (i + 1) % (1 << TDB_HASH_GROUP_BITS)) {
if (group[i] == 0) {
tdb->log(tdb, TDB_DEBUG_ERROR,
tdb->log_priv,
"check: bad group placement"
" %u vs %u\n",
b, bucket);
goto fail;
}
}
if (tdb_read_convert(tdb, off, &rec, sizeof(rec)) == -1)
goto fail;
/* Bottom bits must match header. */
if ((h & ((1 << 5)-1)) != rec_hash(&rec)) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: Bad hash magic at"
" offset %llu (0x%llx vs 0x%llx)\n",
(long long)off,
(long long)h,
(long long)rec_hash(&rec));
goto fail;
}
}
}
tdb_access_release(tdb, hash);
return true;
fail:
tdb_access_release(tdb, hash);
return false;
}
static bool check_hash(struct tdb_context *tdb,
tdb_off_t used[],
size_t num_used)
{
size_t num_found = 0;
if (!check_hash_tree(tdb, offsetof(struct tdb_header, hashtable),
TDB_TOPLEVEL_HASH_BITS-TDB_HASH_GROUP_BITS,
0, 0, used, num_used, &num_found))
return false;
if (num_found != num_used) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: Not all entries are in hash\n");
return false;
}
return true;
}
static bool check_free(struct tdb_context *tdb,
tdb_off_t off,
const struct tdb_free_record *frec,
tdb_off_t prev,
tdb_off_t zone_off, unsigned int bucket)
{
if (frec_magic(frec) != TDB_FREE_MAGIC) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: offset %llu bad magic 0x%llx\n",
(long long)off, (long long)frec->magic_and_meta);
return false;
}
if (tdb->methods->oob(tdb, off
+ frec->data_len+sizeof(struct tdb_used_record),
false))
return false;
if (off < zone_off || off >= zone_off + (1ULL<log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: offset %llu outside zone %llu-%llu\n",
(long long)off,
(long long)zone_off,
(long long)zone_off + (1ULL<data_len) != bucket) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: offset %llu in wrong bucket %u vs %u\n",
(long long)off,
bucket,
size_to_bucket(frec_zone_bits(frec), frec->data_len));
return false;
}
if (prev != frec->prev) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: offset %llu bad prev %llu vs %llu\n",
(long long)off,
(long long)prev, (long long)frec->prev);
return false;
}
return true;
}
static tdb_len_t check_free_list(struct tdb_context *tdb,
tdb_off_t zone_off,
tdb_off_t free[],
size_t num_free,
size_t *num_found)
{
struct free_zone_header zhdr;
tdb_off_t h;
unsigned int i;
if (tdb_read_convert(tdb, zone_off, &zhdr, sizeof(zhdr)) == -1)
return TDB_OFF_ERR;
for (i = 0; i <= BUCKETS_FOR_ZONE(zhdr.zone_bits); i++) {
tdb_off_t off, prev = 0, *p;
struct tdb_free_record f;
h = bucket_off(zone_off, i);
for (off = tdb_read_off(tdb, h); off; off = f.next) {
if (off == TDB_OFF_ERR)
return TDB_OFF_ERR;
if (tdb_read_convert(tdb, off, &f, sizeof(f)))
return TDB_OFF_ERR;
if (!check_free(tdb, off, &f, prev, zone_off, i))
return TDB_OFF_ERR;
/* FIXME: Check hash bits */
p = asearch(&off, free, num_free, off_cmp);
if (!p) {
tdb->log(tdb, TDB_DEBUG_ERROR,
tdb->log_priv,
"tdb_check: Invalid offset"
" %llu in free table\n",
(long long)off);
return TDB_OFF_ERR;
}
/* Mark it invalid. */
*p ^= 1;
(*num_found)++;
prev = off;
}
}
return 1ULL << zhdr.zone_bits;
}
static tdb_off_t check_zone(struct tdb_context *tdb, tdb_off_t zone_off,
tdb_off_t **used, size_t *num_used,
tdb_off_t **free, size_t *num_free,
unsigned int *max_zone_bits)
{
struct free_zone_header zhdr;
tdb_off_t off, hdrlen;
tdb_len_t len;
if (tdb_read_convert(tdb, zone_off, &zhdr, sizeof(zhdr)) == -1)
return TDB_OFF_ERR;
if (zhdr.zone_bits < INITIAL_ZONE_BITS) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"check: bad zone_bits %llu at zone %llu\n",
(long long)zhdr.zone_bits, (long long)zone_off);
return TDB_OFF_ERR;
}
/* Zone bits can only increase... */
if (zhdr.zone_bits > *max_zone_bits)
*max_zone_bits = zhdr.zone_bits;
else if (zhdr.zone_bits < *max_zone_bits) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"check: small zone_bits %llu at zone %llu\n",
(long long)zhdr.zone_bits, (long long)zone_off);
return TDB_OFF_ERR;
}
/* Zone must be within file! */
if (tdb->methods->oob(tdb, zone_off + (1ULL << zhdr.zone_bits), false))
return TDB_OFF_ERR;
hdrlen = sizeof(zhdr)
+ (BUCKETS_FOR_ZONE(zhdr.zone_bits) + 1) * sizeof(tdb_off_t);
for (off = zone_off + hdrlen;
off < zone_off + (1ULL << zhdr.zone_bits);
off += len) {
union {
struct tdb_used_record u;
struct tdb_free_record f;
} pad, *p;
p = tdb_get(tdb, off, &pad, sizeof(pad));
if (!p)
return TDB_OFF_ERR;
if (frec_magic(&p->f) == TDB_FREE_MAGIC) {
if (frec_zone_bits(&p->f) != zhdr.zone_bits) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: Bad free zone bits %u"
" at offset %llu\n",
frec_zone_bits(&p->f),
(long long)off);
return TDB_OFF_ERR;
}
/* This record is free! */
if (!append(free, num_free, off))
return TDB_OFF_ERR;
len = sizeof(p->u) + p->f.data_len;
if (off + len > zone_off + (1ULL << zhdr.zone_bits)) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: free overlength %llu"
" at offset %llu\n",
(long long)len, (long long)off);
return TDB_OFF_ERR;
}
} else {
uint64_t klen, dlen, extra;
/* This record is used! */
if (rec_magic(&p->u) != TDB_MAGIC) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: Bad magic 0x%llx"
" at offset %llu\n",
(long long)rec_magic(&p->u),
(long long)off);
return TDB_OFF_ERR;
}
if (rec_zone_bits(&p->u) != zhdr.zone_bits) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: Bad zone bits %u"
" at offset %llu\n",
rec_zone_bits(&p->u),
(long long)off);
return TDB_OFF_ERR;
}
if (!append(used, num_used, off))
return TDB_OFF_ERR;
klen = rec_key_length(&p->u);
dlen = rec_data_length(&p->u);
extra = rec_extra_padding(&p->u);
len = sizeof(p->u) + klen + dlen + extra;
if (off + len > zone_off + (1ULL << zhdr.zone_bits)) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: used overlength %llu"
" at offset %llu\n",
(long long)len, (long long)off);
return TDB_OFF_ERR;
}
if (len < sizeof(p->f)) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: too short record %llu at"
" %llu\n",
(long long)len, (long long)off);
return TDB_OFF_ERR;
}
}
}
return 1ULL << zhdr.zone_bits;
}
/* FIXME: call check() function. */
int tdb_check(struct tdb_context *tdb,
int (*check)(TDB_DATA key, TDB_DATA data, void *private_data),
void *private_data)
{
tdb_off_t *free = NULL, *used = NULL, off;
tdb_len_t len;
size_t num_free = 0, num_used = 0, num_found = 0;
unsigned max_zone_bits = INITIAL_ZONE_BITS;
uint8_t tailer;
if (tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, false) != 0)
return -1;
if (tdb_lock_expand(tdb, F_RDLCK) != 0) {
tdb_allrecord_unlock(tdb, F_RDLCK);
return -1;
}
if (!check_header(tdb))
goto fail;
/* First we do a linear scan, checking all records. */
for (off = sizeof(struct tdb_header);
off < tdb->map_size - 1;
off += len) {
len = check_zone(tdb, off, &used, &num_used, &free, &num_free,
&max_zone_bits);
if (len == TDB_OFF_ERR)
goto fail;
}
/* Check tailer. */
if (tdb->methods->read(tdb, tdb->map_size - 1, &tailer, 1) == -1)
goto fail;
if (tailer != max_zone_bits) {
tdb->ecode = TDB_ERR_CORRUPT;
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: Bad tailer value %u vs %u\n", tailer,
max_zone_bits);
goto fail;
}
/* FIXME: Check key uniqueness? */
if (!check_hash(tdb, used, num_used))
goto fail;
for (off = sizeof(struct tdb_header);
off < tdb->map_size - 1;
off += len) {
len = check_free_list(tdb, off, free, num_free, &num_found);
if (len == TDB_OFF_ERR)
goto fail;
}
if (num_found != num_free) {
tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
"tdb_check: Not all entries are in free table\n");
return false;
}
tdb_allrecord_unlock(tdb, F_RDLCK);
tdb_unlock_expand(tdb, F_RDLCK);
return 0;
fail:
tdb_allrecord_unlock(tdb, F_RDLCK);
tdb_unlock_expand(tdb, F_RDLCK);
return -1;
}