/*
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, tdb_off_t *recovery)
{
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_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"check: hash test %llu should be %llu",
(long long)hdr.hash_test,
(long long)hash_test);
return false;
}
if (strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) {
tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"check: bad magic '%.*s'",
(unsigned)sizeof(hdr.magic_food), hdr.magic_food);
return false;
}
*recovery = hdr.recovery;
if (*recovery) {
if (*recovery < sizeof(hdr) || *recovery > tdb->map_size) {
tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"tdb_check: invalid recovery offset %zu",
(size_t)*recovery);
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,
int (*check)(TDB_DATA, TDB_DATA, void *),
void *private_data);
static bool check_hash_chain(struct tdb_context *tdb,
tdb_off_t off,
uint64_t hash,
tdb_off_t used[],
size_t num_used,
size_t *num_found,
int (*check)(TDB_DATA, TDB_DATA, void *),
void *private_data)
{
struct tdb_used_record rec;
if (tdb_read_convert(tdb, off, &rec, sizeof(rec)) == -1)
return false;
if (rec_data_length(&rec) != sizeof(struct tdb_chain)) {
tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"tdb_check: Bad hash chain length %llu vs %zu",
(long long)rec_data_length(&rec),
sizeof(struct tdb_chain));
return false;
}
if (rec_key_length(&rec) != 0) {
tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"tdb_check: Bad hash chain key length %llu",
(long long)rec_key_length(&rec));
return false;
}
if (rec_hash(&rec) != 2) {
tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"tdb_check: Bad hash chain hash value %llu",
(long long)rec_hash(&rec));
return false;
}
off += sizeof(rec);
if (!check_hash_tree(tdb, off, 0, hash, 64,
used, num_used, num_found, check, private_data))
return false;
off = tdb_read_off(tdb, off + offsetof(struct tdb_chain, next));
if (off == TDB_OFF_ERR)
return false;
if (off == 0)
return true;
(*num_found)++;
return check_hash_chain(tdb, off, hash, used, num_used, num_found,
check, private_data);
}
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,
int (*check)(TDB_DATA, TDB_DATA, void *),
void *private_data)
{
struct tdb_used_record rec;
if (hprefix_bits >= 64)
return check_hash_chain(tdb, off, hprefix, used, num_used,
num_found, check, private_data);
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_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"tdb_check: Bad hash table length %llu vs %llu",
(long long)rec_data_length(&rec),
(long long)sizeof(tdb_off_t)
<< TDB_SUBLEVEL_HASH_BITS);
return false;
}
if (rec_key_length(&rec) != 0) {
tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"tdb_check: Bad hash table key length %llu",
(long long)rec_key_length(&rec));
return false;
}
if (rec_hash(&rec) != 0) {
tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"tdb_check: Bad hash table hash value %llu",
(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, check, private_data);
}
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,
int (*check)(TDB_DATA, TDB_DATA, void *),
void *private_data)
{
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_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"tdb_check: Invalid offset %llu "
"in hash", (long long)off);
goto fail;
}
/* Mark it invalid. */
*p ^= 1;
(*num_found)++;
if (hprefix_bits == 64) {
/* Chained entries are unordered. */
if (is_subhash(group[b])) {
tdb_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"tdb_check: Invalid chain"
" entry subhash");
goto fail;
}
h = hash_record(tdb, off);
if (h != hprefix) {
tdb_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"check: bad hash chain"
" placement"
" 0x%llx vs 0x%llx",
(long long)h,
(long long)hprefix);
goto fail;
}
if (tdb_read_convert(tdb, off, &rec,
sizeof(rec)))
goto fail;
goto check;
}
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,
check, private_data))
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_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"check: bad hash placement"
" 0x%llx vs 0x%llx",
(long long)h, (long long)hprefix);
goto fail;
}
/* Does it belong in this group? */
if (get_bits(h, group_bits, &used_bits) != g) {
tdb_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"check: bad group %llu vs %u",
(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_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"check: bad bucket %u vs %u",
(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_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"check: bad group placement"
" %u vs %u",
b, bucket);
goto fail;
}
}
if (tdb_read_convert(tdb, off, &rec, sizeof(rec)))
goto fail;
/* Bottom bits must match header. */
if ((h & ((1 << 11)-1)) != rec_hash(&rec)) {
tdb_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"tdb_check: Bad hash magic at"
" offset %llu (0x%llx vs 0x%llx)",
(long long)off,
(long long)h,
(long long)rec_hash(&rec));
goto fail;
}
check:
if (check) {
TDB_DATA key, data;
key.dsize = rec_key_length(&rec);
data.dsize = rec_data_length(&rec);
key.dptr = (void *)tdb_access_read(tdb,
off + sizeof(rec),
key.dsize + data.dsize,
false);
if (!key.dptr)
goto fail;
data.dptr = key.dptr + key.dsize;
if (check(key, data, private_data) != 0)
goto fail;
tdb_access_release(tdb, key.dptr);
}
}
}
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_flists,
int (*check)(TDB_DATA, TDB_DATA, void *),
void *private_data)
{
/* Free lists also show up as used. */
size_t num_found = num_flists;
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,
check, private_data))
return false;
if (num_found != num_used) {
tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"tdb_check: Not all entries are in hash");
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, unsigned int flist, unsigned int bucket)
{
if (frec_magic(frec) != TDB_FREE_MAGIC) {
tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"tdb_check: offset %llu bad magic 0x%llx",
(long long)off, (long long)frec->magic_and_prev);
return false;
}
if (frec_flist(frec) != flist) {
tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"tdb_check: offset %llu bad freelist %u",
(long long)off, frec_flist(frec));
return false;
}
if (tdb->methods->oob(tdb, off
+ frec_len(frec) + sizeof(struct tdb_used_record),
false))
return false;
if (size_to_bucket(frec_len(frec)) != bucket) {
tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"tdb_check: offset %llu in wrong bucket %u vs %u",
(long long)off,
bucket, size_to_bucket(frec_len(frec)));
return false;
}
if (prev != frec_prev(frec)) {
tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"tdb_check: offset %llu bad prev %llu vs %llu",
(long long)off,
(long long)prev, (long long)frec_len(frec));
return false;
}
return true;
}
static bool check_free_list(struct tdb_context *tdb,
tdb_off_t flist_off,
unsigned flist_num,
tdb_off_t free[],
size_t num_free,
size_t *num_found)
{
struct tdb_freelist flist;
tdb_off_t h;
unsigned int i;
if (tdb_read_convert(tdb, flist_off, &flist, sizeof(flist)) == -1)
return false;
if (rec_magic(&flist.hdr) != TDB_MAGIC
|| rec_key_length(&flist.hdr) != 0
|| rec_data_length(&flist.hdr) != sizeof(flist) - sizeof(flist.hdr)
|| rec_hash(&flist.hdr) != 1) {
tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"tdb_check: Invalid header on free list");
return false;
}
for (i = 0; i < TDB_FREE_BUCKETS; i++) {
tdb_off_t off, prev = 0, *p;
struct tdb_free_record f;
h = bucket_off(flist_off, i);
for (off = tdb_read_off(tdb, h); off; off = f.next) {
if (off == TDB_OFF_ERR)
return false;
if (tdb_read_convert(tdb, off, &f, sizeof(f)))
return false;
if (!check_free(tdb, off, &f, prev, flist_num, i))
return false;
/* FIXME: Check hash bits */
p = asearch(&off, free, num_free, off_cmp);
if (!p) {
tdb_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"tdb_check: Invalid offset"
" %llu in free table",
(long long)off);
return false;
}
/* Mark it invalid. */
*p ^= 1;
(*num_found)++;
prev = off;
}
}
return true;
}
/* Slow, but should be very rare. */
size_t dead_space(struct tdb_context *tdb, tdb_off_t off)
{
size_t len;
for (len = 0; off + len < tdb->map_size; len++) {
char c;
if (tdb->methods->read(tdb, off, &c, 1))
return 0;
if (c != 0 && c != 0x43)
break;
}
return len;
}
static bool check_linear(struct tdb_context *tdb,
tdb_off_t **used, size_t *num_used,
tdb_off_t **free, size_t *num_free,
tdb_off_t recovery)
{
tdb_off_t off;
tdb_len_t len;
bool found_recovery = false;
for (off = sizeof(struct tdb_header); off < tdb->map_size; off += len) {
union {
struct tdb_used_record u;
struct tdb_free_record f;
struct tdb_recovery_record r;
} rec;
/* r is larger: only get that if we need to. */
if (tdb_read_convert(tdb, off, &rec, sizeof(rec.f)) == -1)
return false;
/* If we crash after ftruncate, we can get zeroes or fill. */
if (rec.r.magic == TDB_RECOVERY_INVALID_MAGIC
|| rec.r.magic == 0x4343434343434343ULL) {
if (tdb_read_convert(tdb, off, &rec, sizeof(rec.r)))
return false;
if (recovery == off) {
found_recovery = true;
len = sizeof(rec.r) + rec.r.max_len;
} else {
len = dead_space(tdb, off);
if (len < sizeof(rec.r)) {
tdb_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"tdb_check: invalid dead"
" space at %zu",
(size_t)off);
return false;
}
tdb_logerr(tdb, TDB_SUCCESS, TDB_DEBUG_WARNING,
"Dead space at %zu-%zu (of %zu)",
(size_t)off, (size_t)(off + len),
(size_t)tdb->map_size);
}
} else if (rec.r.magic == TDB_RECOVERY_MAGIC) {
if (tdb_read_convert(tdb, off, &rec, sizeof(rec.r)))
return false;
if (recovery != off) {
tdb_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"tdb_check: unexpected recovery"
" record at offset %zu",
(size_t)off);
return false;
}
if (rec.r.len > rec.r.max_len) {
tdb_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"tdb_check: invalid recovery length"
" %zu", (size_t)rec.r.len);
return false;
}
if (rec.r.eof > tdb->map_size) {
tdb_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"tdb_check: invalid old EOF"
" %zu", (size_t)rec.r.eof);
return false;
}
found_recovery = true;
len = sizeof(rec.r) + rec.r.max_len;
} else if (frec_magic(&rec.f) == TDB_FREE_MAGIC) {
len = sizeof(rec.u) + frec_len(&rec.f);
if (off + len > tdb->map_size) {
tdb_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"tdb_check: free overlength %llu"
" at offset %llu",
(long long)len, (long long)off);
return false;
}
/* This record should be in free lists. */
if (frec_flist(&rec.f) != TDB_FLIST_NONE
&& !append(free, num_free, off))
return false;
} else {
uint64_t klen, dlen, extra;
/* This record is used! */
if (rec_magic(&rec.u) != TDB_MAGIC) {
tdb_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"tdb_check: Bad magic 0x%llx"
" at offset %zu",
(long long)rec_magic(&rec.u),
(size_t)off);
return false;
}
if (!append(used, num_used, off))
return false;
klen = rec_key_length(&rec.u);
dlen = rec_data_length(&rec.u);
extra = rec_extra_padding(&rec.u);
len = sizeof(rec.u) + klen + dlen + extra;
if (off + len > tdb->map_size) {
tdb_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"tdb_check: used overlength %llu"
" at offset %llu",
(long long)len, (long long)off);
return false;
}
if (len < sizeof(rec.f)) {
tdb_logerr(tdb, TDB_ERR_CORRUPT,
TDB_DEBUG_ERROR,
"tdb_check: too short record %llu"
" at %llu",
(long long)len, (long long)off);
return false;
}
}
}
/* We must have found recovery area if there was one. */
if (recovery != 0 && !found_recovery) {
tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"tdb_check: expected a recovery area at %zu",
(size_t)recovery);
return false;
}
return true;
}
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, flist, recovery;
size_t num_free = 0, num_used = 0, num_found = 0, num_flists = 0;
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, &recovery))
goto fail;
/* First we do a linear scan, checking all records. */
if (!check_linear(tdb, &used, &num_used, &free, &num_free, recovery))
goto fail;
for (flist = first_flist(tdb); flist; flist = next_flist(tdb, flist)) {
if (flist == TDB_OFF_ERR)
goto fail;
if (!check_free_list(tdb, flist, num_flists, free, num_free,
&num_found))
goto fail;
num_flists++;
}
/* FIXME: Check key uniqueness? */
if (!check_hash(tdb, used, num_used, num_flists, check, private_data))
goto fail;
if (num_found != num_free) {
tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
"tdb_check: Not all entries are in free table");
return -1;
}
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;
}