]> git.ozlabs.org Git - ccan/blobdiff - ccan/tdb2/check.c
tdb2: rename ->read and ->write functions.
[ccan] / ccan / tdb2 / check.c
index 5a16dbf42798e0d351b6fe0f5c424e00703936a9..4da81dbbbb53fa68ab1031fabaaccbc95f3dca2a 100644 (file)
@@ -30,7 +30,7 @@ static bool append(tdb_off_t **arr, size_t *num, tdb_off_t off)
        return true;
 }
 
-static bool check_header(struct tdb_context *tdb)
+static bool check_header(struct tdb_context *tdb, tdb_off_t *recovery)
 {
        uint64_t hash_test;
        struct tdb_header hdr;
@@ -43,20 +43,30 @@ static bool check_header(struct tdb_context *tdb)
        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);
+               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->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-                        "check: bad magic '%.*s'\n",
-                        (unsigned)sizeof(hdr.magic_food), hdr.magic_food);
+               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;
 }
@@ -67,7 +77,65 @@ static bool check_hash_tree(struct tdb_context *tdb,
                            unsigned hprefix_bits,
                            tdb_off_t used[],
                            size_t num_used,
-                           size_t *num_found);
+                           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_magic(&rec) != TDB_CHAIN_MAGIC) {
+               tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
+                          "tdb_check: Bad hash chain magic %llu",
+                          (long long)rec_magic(&rec));
+               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) != 0) {
+               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,
@@ -75,30 +143,43 @@ static bool check_hash_record(struct tdb_context *tdb,
                              unsigned hprefix_bits,
                              tdb_off_t used[],
                              size_t num_used,
-                             size_t *num_found)
+                             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_magic(&rec) != TDB_HTABLE_MAGIC) {
+               tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
+                          "tdb_check: Bad hash table magic %llu",
+                          (long long)rec_magic(&rec));
+               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)<<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->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-                        "tdb_check: Bad hash table key length %llu\n",
+               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->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-                        "tdb_check: Bad hash table hash value %llu\n",
+               tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
+                        "tdb_check: Bad hash table hash value %llu",
                         (long long)rec_hash(&rec));
                return false;
        }
@@ -107,7 +188,7 @@ static bool check_hash_record(struct tdb_context *tdb,
        return check_hash_tree(tdb, off,
                               TDB_SUBLEVEL_HASH_BITS-TDB_HASH_GROUP_BITS,
                               hprefix, hprefix_bits,
-                              used, num_used, num_found);
+                              used, num_used, num_found, check, private_data);
 }
 
 static int off_cmp(const tdb_off_t *a, const tdb_off_t *b)
@@ -131,7 +212,9 @@ static bool check_hash_tree(struct tdb_context *tdb,
                            unsigned hprefix_bits,
                            tdb_off_t used[],
                            size_t num_used,
-                           size_t *num_found)
+                           size_t *num_found,
+                           int (*check)(TDB_DATA, TDB_DATA, void *),
+                           void *private_data)
 {
        unsigned int g, b;
        const tdb_off_t *hash;
@@ -156,16 +239,42 @@ static bool check_hash_tree(struct tdb_context *tdb,
                        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);
+                               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 
@@ -178,7 +287,8 @@ static bool check_hash_tree(struct tdb_context *tdb,
                                               hprefix_bits
                                                       + group_bits
                                                       + TDB_HASH_GROUP_BITS,
-                                              used, num_used, num_found))
+                                              used, num_used, num_found,
+                                              check, private_data))
                                        goto fail;
                                continue;
                        }
@@ -189,18 +299,20 @@ static bool check_hash_tree(struct tdb_context *tdb,
                        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",
+                               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->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-                                        "check: bad group %llu vs %u\n",
-                                        (long long)h, g);
+                               tdb_logerr(tdb, TDB_ERR_CORRUPT,
+                                          TDB_DEBUG_ERROR,
+                                          "check: bad group %llu vs %u",
+                                          (long long)h, g);
                                goto fail;
                        }
 
@@ -209,11 +321,12 @@ static bool check_hash_tree(struct tdb_context *tdb,
                        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",
+                               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),
+                                                       TDB_HASH_GROUP_BITS,
+                                                       &used_bits),
                                         bucket);
                                goto fail;
                        }
@@ -224,28 +337,46 @@ static bool check_hash_tree(struct tdb_context *tdb,
                             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);
+                                       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)) == -1)
+                       if (tdb_read_convert(tdb, off, &rec, sizeof(rec)))
                                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));
+                       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);
@@ -258,18 +389,22 @@ fail:
 
 static bool check_hash(struct tdb_context *tdb,
                       tdb_off_t used[],
-                      size_t num_used)
+                      size_t num_used, size_t num_ftables,
+                      int (*check)(TDB_DATA, TDB_DATA, void *),
+                      void *private_data)
 {
-       size_t num_found = 0;
+       /* Free tables also show up as used. */
+       size_t num_found = num_ftables;
 
        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))
+                            0, 0, used, num_used, &num_found,
+                            check, private_data))
                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");
+               tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
+                          "tdb_check: Not all entries are in hash");
                return false;
        }
        return true;
@@ -278,80 +413,88 @@ static bool check_hash(struct tdb_context *tdb,
 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)
+                      tdb_off_t prev, unsigned int ftable,
+                      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);
+               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_ftable(frec) != ftable) {
+               tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
+                          "tdb_check: offset %llu bad freetable %u",
+                          (long long)off, frec_ftable(frec));
+               return false;
+       }
+
        if (tdb->methods->oob(tdb, off
-                             + frec->data_len+sizeof(struct tdb_used_record),
+                             + frec_len(frec) + sizeof(struct tdb_used_record),
                              false))
                return false;
-       if (off < zone_off || off >= zone_off + (1ULL<<frec_zone_bits(frec))) {
-               tdb->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<<frec_zone_bits(frec)));
-               return false;
-       }
-       if (size_to_bucket(frec_zone_bits(frec), frec->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));
+       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) {
-               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);
+       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 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)
+static bool check_free_table(struct tdb_context *tdb,
+                            tdb_off_t ftable_off,
+                            unsigned ftable_num,
+                            tdb_off_t fr[],
+                            size_t num_free,
+                            size_t *num_found)
 {
-       struct free_zone_header zhdr;
+       struct tdb_freetable ft;
        tdb_off_t h;
        unsigned int i;
 
-       if (tdb_read_convert(tdb, zone_off, &zhdr, sizeof(zhdr)) == -1)
-               return TDB_OFF_ERR;
+       if (tdb_read_convert(tdb, ftable_off, &ft, sizeof(ft)) == -1)
+               return false;
 
-       for (i = 0; i <= BUCKETS_FOR_ZONE(zhdr.zone_bits); i++) {
+       if (rec_magic(&ft.hdr) != TDB_FTABLE_MAGIC
+           || rec_key_length(&ft.hdr) != 0
+           || rec_data_length(&ft.hdr) != sizeof(ft) - sizeof(ft.hdr)
+           || rec_hash(&ft.hdr) != 0) {
+               tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
+                          "tdb_check: Invalid header on free table");
+               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(zone_off, i);
+               h = bucket_off(ftable_off, i);
                for (off = tdb_read_off(tdb, h); off; off = f.next) {
                        if (off == TDB_OFF_ERR)
-                               return TDB_OFF_ERR;
+                               return false;
                        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;
+                               return false;
+                       if (!check_free(tdb, off, &f, prev, ftable_num, i))
+                               return false;
 
                        /* FIXME: Check hash bits */
-                       p = asearch(&off, free, num_free, off_cmp);
+                       p = asearch(&off, fr, 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;
+                               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;
@@ -359,138 +502,167 @@ static tdb_len_t check_free_list(struct tdb_context *tdb,
                        prev = off;
                }
        }
-       return 1ULL << zhdr.zone_bits;
+       return true;
 }
 
-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)
+/* Slow, but should be very rare. */
+size_t dead_space(struct tdb_context *tdb, tdb_off_t off)
 {
-       struct free_zone_header zhdr;
-       tdb_off_t off, hdrlen, end;
-       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;
+       size_t len;
+
+       for (len = 0; off + len < tdb->map_size; len++) {
+               char c;
+               if (tdb->methods->tread(tdb, off, &c, 1))
+                       return 0;
+               if (c != 0 && c != 0x43)
+                       break;
        }
+       return len;
+}
 
-       /* Zone header must be within file! */
-       hdrlen = sizeof(zhdr)
-               + (BUCKETS_FOR_ZONE(zhdr.zone_bits) + 1) * sizeof(tdb_off_t);
-
-       if (tdb->methods->oob(tdb, zone_off + hdrlen, true))
-               return TDB_OFF_ERR;
-
-       end = zone_off + (1ULL << zhdr.zone_bits);
-       if (end > tdb->map_size)
-               end = tdb->map_size;
+static bool check_linear(struct tdb_context *tdb,
+                        tdb_off_t **used, size_t *num_used,
+                        tdb_off_t **fr, size_t *num_free,
+                        tdb_off_t recovery)
+{
+       tdb_off_t off;
+       tdb_len_t len;
+       bool found_recovery = false;
 
-       for (off = zone_off + hdrlen; off < end; off += len) {
+       for (off = sizeof(struct tdb_header); off < tdb->map_size; 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
-                   || frec_magic(&p->f) == TDB_COALESCING_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;
+                       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);
                        }
-                       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 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;
                        }
-                       /* This record is free! */
-                       if (frec_magic(&p->f) == TDB_FREE_MAGIC
-                           && !append(free, num_free, off))
-                               return TDB_OFF_ERR;
-               } else {
+                       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_ftable(&rec.f) != TDB_FTABLE_NONE
+                           && !append(fr, num_free, off))
+                               return false;
+               } else if (rec_magic(&rec.u) == TDB_USED_MAGIC
+                          || rec_magic(&rec.u) == TDB_CHAIN_MAGIC
+                          || rec_magic(&rec.u) == TDB_HTABLE_MAGIC
+                          || rec_magic(&rec.u) == TDB_FTABLE_MAGIC) {
                        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;
+                               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(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;
+                       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;
                        }
+               } else {
+                       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;
                }
        }
-       return off - zone_off;
+
+       /* 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;
 }
 
-/* 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;
+       tdb_off_t *fr = NULL, *used = NULL, ft, recovery;
+       size_t num_free = 0, num_used = 0, num_found = 0, num_ftables = 0;
 
        if (tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, false) != 0)
                return -1;
@@ -500,34 +672,30 @@ int tdb_check(struct tdb_context *tdb,
                return -1;
        }
 
-       if (!check_header(tdb))
+       if (!check_header(tdb, &recovery))
                goto fail;
 
        /* First we do a linear scan, checking all records. */
-       for (off = sizeof(struct tdb_header);
-            off < tdb->map_size;
-            off += len) {
-               len = check_zone(tdb, off, &used, &num_used, &free, &num_free,
-                                &max_zone_bits);
-               if (len == TDB_OFF_ERR)
+       if (!check_linear(tdb, &used, &num_used, &fr, &num_free, recovery))
+               goto fail;
+
+       for (ft = first_ftable(tdb); ft; ft = next_ftable(tdb, ft)) {
+               if (ft == TDB_OFF_ERR)
                        goto fail;
+               if (!check_free_table(tdb, ft, num_ftables, fr, num_free,
+                                     &num_found))
+                       goto fail;
+               num_ftables++;
        }
 
        /* FIXME: Check key uniqueness? */
-       if (!check_hash(tdb, used, num_used))
+       if (!check_hash(tdb, used, num_used, num_ftables, check, private_data))
                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_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);