From: Rusty Russell <rusty@rustcorp.com.au>
Date: Wed, 1 Dec 2010 13:15:56 +0000 (+1030)
Subject: tdb2: use separate magic constants for chain, htable and ftable entries
X-Git-Url: https://git.ozlabs.org/?p=ccan;a=commitdiff_plain;h=2491b65a6d10cd6ca1a3e05bf535eb0180047922

tdb2: use separate magic constants for chain, htable and ftable entries

Rather than overloading TDB_USED_MAGIC and the hash value as we do now.
We also rename "free list" to the more-accurate "free table" everywhere.
---

diff --git a/ccan/tdb2/check.c b/ccan/tdb2/check.c
index 8c7ed1c4..d614d4cb 100644
--- a/ccan/tdb2/check.c
+++ b/ccan/tdb2/check.c
@@ -95,6 +95,13 @@ static bool check_hash_chain(struct tdb_context *tdb,
 	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",
@@ -108,7 +115,7 @@ static bool check_hash_chain(struct tdb_context *tdb,
 			 (long long)rec_key_length(&rec));
 		return false;
 	}
-	if (rec_hash(&rec) != 2) {
+	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));
@@ -149,6 +156,12 @@ static bool check_hash_record(struct tdb_context *tdb,
 	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_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
@@ -376,12 +389,12 @@ fail:
 
 static bool check_hash(struct tdb_context *tdb,
 		       tdb_off_t used[],
-		       size_t num_used, size_t num_flists,
+		       size_t num_used, size_t num_ftables,
 		       int (*check)(TDB_DATA, TDB_DATA, void *),
 		       void *private_data)
 {
-	/* Free lists also show up as used. */
-	size_t num_found = num_flists;
+	/* 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,
@@ -400,7 +413,8 @@ 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, unsigned int flist, unsigned int bucket)
+		       tdb_off_t prev, unsigned int ftable,
+		       unsigned int bucket)
 {
 	if (frec_magic(frec) != TDB_FREE_MAGIC) {
 		tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
@@ -408,10 +422,10 @@ static bool check_free(struct tdb_context *tdb,
 			   (long long)off, (long long)frec->magic_and_prev);
 		return false;
 	}
-	if (frec_flist(frec) != flist) {
+	if (frec_ftable(frec) != ftable) {
 		tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_ERROR,
-			   "tdb_check: offset %llu bad freelist %u",
-			   (long long)off, frec_flist(frec));
+			   "tdb_check: offset %llu bad freetable %u",
+			   (long long)off, frec_ftable(frec));
 		return false;
 	}
 
@@ -436,26 +450,26 @@ static bool check_free(struct tdb_context *tdb,
 	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)
+static bool check_free_table(struct tdb_context *tdb,
+			     tdb_off_t ftable_off,
+			     unsigned ftable_num,
+			     tdb_off_t free[],
+			     size_t num_free,
+			     size_t *num_found)
 {
-	struct tdb_freelist flist;
+	struct tdb_freetable ft;
 	tdb_off_t h;
 	unsigned int i;
 
-	if (tdb_read_convert(tdb, flist_off, &flist, sizeof(flist)) == -1)
+	if (tdb_read_convert(tdb, ftable_off, &ft, sizeof(ft)) == -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) {
+	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 list");
+			   "tdb_check: Invalid header on free table");
 		return false;
 	}
 
@@ -463,13 +477,13 @@ static bool check_free_list(struct tdb_context *tdb,
 		tdb_off_t off, prev = 0, *p;
 		struct tdb_free_record f;
 
-		h = bucket_off(flist_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 false;
 			if (tdb_read_convert(tdb, off, &f, sizeof(f)))
 				return false;
-			if (!check_free(tdb, off, &f, prev, flist_num, i))
+			if (!check_free(tdb, off, &f, prev, ftable_num, i))
 				return false;
 
 			/* FIXME: Check hash bits */
@@ -588,23 +602,16 @@ static bool check_linear(struct tdb_context *tdb,
 				return false;
 			}
 			/* This record should be in free lists. */
-			if (frec_flist(&rec.f) != TDB_FLIST_NONE
+			if (frec_ftable(&rec.f) != TDB_FTABLE_NONE
 			    && !append(free, num_free, off))
 				return false;
-		} else {
+		} 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(&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;
 
@@ -630,6 +637,12 @@ static bool check_linear(struct tdb_context *tdb,
 					   (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;
 		}
 	}
 
@@ -648,8 +661,8 @@ 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;
+	tdb_off_t *free = 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;
@@ -666,17 +679,17 @@ int tdb_check(struct tdb_context *tdb,
 	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)
+	for (ft = first_ftable(tdb); ft; ft = next_ftable(tdb, ft)) {
+		if (ft == TDB_OFF_ERR)
 			goto fail;
-		if (!check_free_list(tdb, flist, num_flists, free, num_free,
-				     &num_found))
+		if (!check_free_table(tdb, ft, num_ftables, free, num_free,
+				      &num_found))
 			goto fail;
-		num_flists++;
+		num_ftables++;
 	}
 
 	/* FIXME: Check key uniqueness? */
-	if (!check_hash(tdb, used, num_used, num_flists, check, private_data))
+	if (!check_hash(tdb, used, num_used, num_ftables, check, private_data))
 		goto fail;
 
 	if (num_found != num_free) {
diff --git a/ccan/tdb2/free.c b/ccan/tdb2/free.c
index b41e1d58..5d1bd3c6 100644
--- a/ccan/tdb2/free.c
+++ b/ccan/tdb2/free.c
@@ -49,24 +49,24 @@ unsigned int size_to_bucket(tdb_len_t data_len)
 	return bucket;
 }
 
-tdb_off_t first_flist(struct tdb_context *tdb)
+tdb_off_t first_ftable(struct tdb_context *tdb)
 {
-	return tdb_read_off(tdb, offsetof(struct tdb_header, free_list));
+	return tdb_read_off(tdb, offsetof(struct tdb_header, free_table));
 }
 
-tdb_off_t next_flist(struct tdb_context *tdb, tdb_off_t flist)
+tdb_off_t next_ftable(struct tdb_context *tdb, tdb_off_t ftable)
 {
-	return tdb_read_off(tdb, flist + offsetof(struct tdb_freelist, next));
+	return tdb_read_off(tdb, ftable + offsetof(struct tdb_freetable,next));
 }
 
-int tdb_flist_init(struct tdb_context *tdb)
+int tdb_ftable_init(struct tdb_context *tdb)
 {
 	/* Use reservoir sampling algorithm to select a free list at random. */
 	unsigned int rnd, max = 0, count = 0;
 	tdb_off_t off;
 
-	tdb->flist_off = off = first_flist(tdb);
-	tdb->flist = 0;
+	tdb->ftable_off = off = first_ftable(tdb);
+	tdb->ftable = 0;
 
 	while (off) {
 		if (off == TDB_OFF_ERR)
@@ -74,31 +74,31 @@ int tdb_flist_init(struct tdb_context *tdb)
 
 		rnd = random();
 		if (rnd >= max) {
-			tdb->flist_off = off;
-			tdb->flist = count;
+			tdb->ftable_off = off;
+			tdb->ftable = count;
 			max = rnd;
 		}
 
-		off = next_flist(tdb, off);
+		off = next_ftable(tdb, off);
 		count++;
 	}
 	return 0;
 }
 
 /* Offset of a given bucket. */
-tdb_off_t bucket_off(tdb_off_t flist_off, unsigned bucket)
+tdb_off_t bucket_off(tdb_off_t ftable_off, unsigned bucket)
 {
-	return flist_off + offsetof(struct tdb_freelist, buckets)
+	return ftable_off + offsetof(struct tdb_freetable, buckets)
 		+ bucket * sizeof(tdb_off_t);
 }
 
 /* Returns free_buckets + 1, or list number to search. */
 static tdb_off_t find_free_head(struct tdb_context *tdb,
-				tdb_off_t flist_off,
+				tdb_off_t ftable_off,
 				tdb_off_t bucket)
 {
 	/* Speculatively search for a non-zero bucket. */
-	return tdb_find_nonzero_off(tdb, bucket_off(flist_off, 0),
+	return tdb_find_nonzero_off(tdb, bucket_off(ftable_off, 0),
 				    bucket, TDB_FREE_BUCKETS);
 }
 
@@ -159,8 +159,8 @@ static int enqueue_in_free(struct tdb_context *tdb,
 	struct tdb_free_record new;
 	uint64_t magic = (TDB_FREE_MAGIC << (64 - TDB_OFF_UPPER_STEAL));
 
-	/* We only need to set flist_and_len; rest is set in enqueue_in_free */
-	new.flist_and_len = ((uint64_t)tdb->flist << (64 - TDB_OFF_UPPER_STEAL))
+	/* We only need to set ftable_and_len; rest is set in enqueue_in_free */
+	new.ftable_and_len = ((uint64_t)tdb->ftable << (64 - TDB_OFF_UPPER_STEAL))
 		| len;
 	/* prev = 0. */
 	new.magic_and_prev = magic;
@@ -209,7 +209,7 @@ int add_free_record(struct tdb_context *tdb,
 
 	len = len_with_header - sizeof(struct tdb_used_record);
 
-	b_off = bucket_off(tdb->flist_off, size_to_bucket(len));
+	b_off = bucket_off(tdb->ftable_off, size_to_bucket(len));
 	if (tdb_lock_free_bucket(tdb, b_off, TDB_LOCK_WAIT) != 0)
 		return -1;
 
@@ -245,17 +245,17 @@ static size_t record_leftover(size_t keylen, size_t datalen,
 	return leftover;
 }
 
-static tdb_off_t flist_offset(struct tdb_context *tdb, unsigned int flist)
+static tdb_off_t ftable_offset(struct tdb_context *tdb, unsigned int ftable)
 {
 	tdb_off_t off;
 	unsigned int i;
 
-	if (likely(tdb->flist == flist))
-		return tdb->flist_off;
+	if (likely(tdb->ftable == ftable))
+		return tdb->ftable_off;
 
-	off = first_flist(tdb);
-	for (i = 0; i < flist; i++)
-		off = next_flist(tdb, off);
+	off = first_ftable(tdb);
+	for (i = 0; i < ftable; i++)
+		off = next_ftable(tdb, off);
 	return off;
 }
 
@@ -272,21 +272,21 @@ static int coalesce(struct tdb_context *tdb,
 	while (end < tdb->map_size) {
 		const struct tdb_free_record *r;
 		tdb_off_t nb_off;
-		unsigned flist, bucket;
+		unsigned ftable, bucket;
 
 		r = tdb_access_read(tdb, end, sizeof(*r), true);
 		if (!r)
 			goto err;
 
 		if (frec_magic(r) != TDB_FREE_MAGIC
-		    || frec_flist(r) == TDB_FLIST_NONE) {
+		    || frec_ftable(r) == TDB_FTABLE_NONE) {
 			tdb_access_release(tdb, r);
 			break;
 		}
 
-		flist = frec_flist(r);
+		ftable = frec_ftable(r);
 		bucket = size_to_bucket(frec_len(r));
-		nb_off = bucket_off(flist_offset(tdb, flist), bucket);
+		nb_off = bucket_off(ftable_offset(tdb, ftable), bucket);
 		tdb_access_release(tdb, r);
 
 		/* We may be violating lock order here, so best effort. */
@@ -307,7 +307,7 @@ static int coalesce(struct tdb_context *tdb,
 			break;
 		}
 
-		if (unlikely(frec_flist(&rec) != flist)
+		if (unlikely(frec_ftable(&rec) != ftable)
 		    || unlikely(size_to_bucket(frec_len(&rec)) != bucket)) {
 			add_stat(tdb, alloc_coalesce_race, 1);
 			tdb_unlock_free_bucket(tdb, nb_off);
@@ -344,11 +344,11 @@ static int coalesce(struct tdb_context *tdb,
 
 	/* We have to drop this to avoid deadlocks, so make sure record
 	 * doesn't get coalesced by someone else! */
-	rec.flist_and_len = (TDB_FLIST_NONE << (64 - TDB_OFF_UPPER_STEAL))
+	rec.ftable_and_len = (TDB_FTABLE_NONE << (64 - TDB_OFF_UPPER_STEAL))
 		| (end - off - sizeof(struct tdb_used_record));
 	if (tdb_write_off(tdb, off + offsetof(struct tdb_free_record,
-					      flist_and_len),
-			  rec.flist_and_len) != 0)
+					      ftable_and_len),
+			  rec.ftable_and_len) != 0)
 		goto err;
 
 	add_stat(tdb, alloc_coalesce_succeeded, 1);
@@ -366,10 +366,11 @@ err:
 
 /* We need size bytes to put our key and data in. */
 static tdb_off_t lock_and_alloc(struct tdb_context *tdb,
-				tdb_off_t flist_off,
+				tdb_off_t ftable_off,
 				tdb_off_t bucket,
 				size_t keylen, size_t datalen,
 				bool want_extra,
+				unsigned magic,
 				unsigned hashlow)
 {
 	tdb_off_t off, b_off,best_off;
@@ -379,7 +380,7 @@ static tdb_off_t lock_and_alloc(struct tdb_context *tdb,
 
 	add_stat(tdb, allocs, 1);
 again:
-	b_off = bucket_off(flist_off, bucket);
+	b_off = bucket_off(ftable_off, bucket);
 
 	/* FIXME: Try non-blocking wait first, to measure contention. */
 	/* Lock this bucket. */
@@ -387,7 +388,7 @@ again:
 		return TDB_OFF_ERR;
 	}
 
-	best.flist_and_len = -1ULL;
+	best.ftable_and_len = -1ULL;
 	best_off = 0;
 
 	/* Get slack if we're after extra. */
@@ -462,9 +463,8 @@ again:
 		assert(keylen + datalen + leftover <= frec_len(&best));
 		/* We need to mark non-free before we drop lock, otherwise
 		 * coalesce() could try to merge it! */
-		if (set_used_header(tdb, &rec, keylen, datalen,
-				    frec_len(&best) - leftover,
-				    hashlow) != 0)
+		if (set_header(tdb, &rec, magic, keylen, datalen,
+			       frec_len(&best) - leftover, hashlow) != 0)
 			goto unlock_err;
 
 		if (tdb_write_convert(tdb, best_off, &rec, sizeof(rec)) != 0)
@@ -496,10 +496,10 @@ unlock_err:
 /* Get a free block from current free list, or 0 if none. */
 static tdb_off_t get_free(struct tdb_context *tdb,
 			  size_t keylen, size_t datalen, bool want_extra,
-			  unsigned hashlow)
+			  unsigned magic, unsigned hashlow)
 {
-	tdb_off_t off, flist_off;
-	unsigned start_b, b, flist;
+	tdb_off_t off, ftable_off;
+	unsigned start_b, b, ftable;
 	bool wrapped = false;
 
 	/* If they are growing, add 50% to get to higher bucket. */
@@ -509,17 +509,17 @@ static tdb_off_t get_free(struct tdb_context *tdb,
 	else
 		start_b = size_to_bucket(adjust_size(keylen, datalen));
 
-	flist_off = tdb->flist_off;
-	flist = tdb->flist;
-	while (!wrapped || flist_off != tdb->flist_off) {
+	ftable_off = tdb->ftable_off;
+	ftable = tdb->ftable;
+	while (!wrapped || ftable_off != tdb->ftable_off) {
 		/* Start at exact size bucket, and search up... */
-		for (b = find_free_head(tdb, flist_off, start_b);
+		for (b = find_free_head(tdb, ftable_off, start_b);
 		     b < TDB_FREE_BUCKETS;
-		     b = find_free_head(tdb, flist_off, b + 1)) {
+		     b = find_free_head(tdb, ftable_off, b + 1)) {
 			/* Try getting one from list. */
-			off = lock_and_alloc(tdb, flist_off,
+			off = lock_and_alloc(tdb, ftable_off,
 					     b, keylen, datalen, want_extra,
-					     hashlow);
+					     magic, hashlow);
 			if (off == TDB_OFF_ERR)
 				return TDB_OFF_ERR;
 			if (off != 0) {
@@ -528,31 +528,31 @@ static tdb_off_t get_free(struct tdb_context *tdb,
 				if (b == TDB_FREE_BUCKETS - 1)
 					add_stat(tdb, alloc_bucket_max, 1);
 				/* Worked?  Stay using this list. */
-				tdb->flist_off = flist_off;
-				tdb->flist = flist;
+				tdb->ftable_off = ftable_off;
+				tdb->ftable = ftable;
 				return off;
 			}
 			/* Didn't work.  Try next bucket. */
 		}
 
-		/* Hmm, try next list. */
-		flist_off = next_flist(tdb, flist_off);
-		flist++;
+		/* Hmm, try next table. */
+		ftable_off = next_ftable(tdb, ftable_off);
+		ftable++;
 
-		if (flist_off == 0) {
+		if (ftable_off == 0) {
 			wrapped = true;
-			flist_off = first_flist(tdb);
-			flist = 0;
+			ftable_off = first_ftable(tdb);
+			ftable = 0;
 		}
 	}
 
 	return 0;
 }
 
-int set_used_header(struct tdb_context *tdb,
-		    struct tdb_used_record *rec,
-		    uint64_t keylen, uint64_t datalen,
-		    uint64_t actuallen, unsigned hashlow)
+int set_header(struct tdb_context *tdb,
+	       struct tdb_used_record *rec,
+	       unsigned magic, uint64_t keylen, uint64_t datalen,
+	       uint64_t actuallen, unsigned hashlow)
 {
 	uint64_t keybits = (fls64(keylen) + 1) / 2;
 
@@ -560,7 +560,7 @@ int set_used_header(struct tdb_context *tdb,
 	rec->magic_and_meta = (hashlow & ((1 << 11)-1))
 		| ((actuallen - (keylen + datalen)) << 11)
 		| (keybits << 43)
-		| (TDB_MAGIC << 48);
+		| ((uint64_t)magic << 48);
 	rec->key_and_data_len = (keylen | (datalen << (keybits*2)));
 
 	/* Encoding can fail on big values. */
@@ -627,7 +627,7 @@ static int tdb_expand(struct tdb_context *tdb, tdb_len_t size)
 
 /* This won't fail: it will expand the database if it has to. */
 tdb_off_t alloc(struct tdb_context *tdb, size_t keylen, size_t datalen,
-		uint64_t hash, bool growing)
+		uint64_t hash, unsigned magic, bool growing)
 {
 	tdb_off_t off;
 
@@ -635,7 +635,7 @@ tdb_off_t alloc(struct tdb_context *tdb, size_t keylen, size_t datalen,
 	assert(!tdb->direct_access);
 
 	for (;;) {
-		off = get_free(tdb, keylen, datalen, growing, hash);
+		off = get_free(tdb, keylen, datalen, growing, magic, hash);
 		if (likely(off != 0))
 			break;
 
diff --git a/ccan/tdb2/hash.c b/ccan/tdb2/hash.c
index 9263dab2..18f6b172 100644
--- a/ccan/tdb2/hash.c
+++ b/ccan/tdb2/hash.c
@@ -409,8 +409,8 @@ static int COLD add_to_chain(struct tdb_context *tdb,
 			return -1;
 
 		if (!next) {
-			next = alloc(tdb, 0, sizeof(struct tdb_chain), 2,
-				     false);
+			next = alloc(tdb, 0, sizeof(struct tdb_chain), 0,
+				     TDB_CHAIN_MAGIC, false);
 			if (next == TDB_OFF_ERR)
 				return -1;
 			if (zero_out(tdb, next+sizeof(struct tdb_used_record),
@@ -457,7 +457,7 @@ static int add_to_subhash(struct tdb_context *tdb, tdb_off_t subhash,
 
 static int expand_group(struct tdb_context *tdb, struct hash_info *h)
 {
-	unsigned bucket, num_vals, i, hash;
+	unsigned bucket, num_vals, i, magic;
 	size_t subsize;
 	tdb_off_t subhash;
 	tdb_off_t vals[1 << TDB_HASH_GROUP_BITS];
@@ -468,14 +468,14 @@ static int expand_group(struct tdb_context *tdb, struct hash_info *h)
 	if (h->hash_used == 64) {
 		add_stat(tdb, alloc_chain, 1);
 		subsize = sizeof(struct tdb_chain);
-		hash = 2;
+		magic = TDB_CHAIN_MAGIC;
 	} else {
 		add_stat(tdb, alloc_subhash, 1);
 		subsize = (sizeof(tdb_off_t) << TDB_SUBLEVEL_HASH_BITS);
-		hash = 0;
+		magic = TDB_HTABLE_MAGIC;
 	}
 
-	subhash = alloc(tdb, 0, subsize, hash, false);
+	subhash = alloc(tdb, 0, subsize, 0, magic, false);
 	if (subhash == TDB_OFF_ERR)
 		return -1;
 
@@ -703,7 +703,7 @@ int next_in_hash(struct tdb_context *tdb, int ltype,
 						  ltype);
 				return -1;
 			}
-			if (rec_magic(&rec) != TDB_MAGIC) {
+			if (rec_magic(&rec) != TDB_USED_MAGIC) {
 				tdb_logerr(tdb, TDB_ERR_CORRUPT,
 					   TDB_DEBUG_FATAL,
 					   "next_in_hash:"
diff --git a/ccan/tdb2/lock.c b/ccan/tdb2/lock.c
index 0b30af54..88dbdd42 100644
--- a/ccan/tdb2/lock.c
+++ b/ccan/tdb2/lock.c
@@ -495,12 +495,12 @@ again:
 		return -1;
 	}
 
-	/* Lock free lists: there to end of file. */
+	/* Lock free tables: there to end of file. */
 	if (tdb_brlock(tdb, ltype, TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE,
 		       0, flags)) {
 		if (!(flags & TDB_LOCK_PROBE)) {
 			tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_ERROR,
-				 "tdb_allrecord_lock freelist failed");
+				 "tdb_allrecord_lock freetables failed");
 		}
 		tdb_brunlock(tdb, ltype, TDB_HASH_LOCK_START, 
 			     TDB_HASH_LOCK_RANGE);
diff --git a/ccan/tdb2/private.h b/ccan/tdb2/private.h
index 01172732..09f447f9 100644
--- a/ccan/tdb2/private.h
+++ b/ccan/tdb2/private.h
@@ -64,7 +64,10 @@ typedef uint64_t tdb_off_t;
 
 #define TDB_MAGIC_FOOD "TDB file\n"
 #define TDB_VERSION ((uint64_t)(0x26011967 + 7))
-#define TDB_MAGIC ((uint64_t)0x1999)
+#define TDB_USED_MAGIC ((uint64_t)0x1999)
+#define TDB_HTABLE_MAGIC ((uint64_t)0x1888)
+#define TDB_CHAIN_MAGIC ((uint64_t)0x1777)
+#define TDB_FTABLE_MAGIC ((uint64_t)0x1666)
 #define TDB_FREE_MAGIC ((uint64_t)0xFE)
 #define TDB_HASH_MAGIC (0xA1ABE11A01092008ULL)
 #define TDB_RECOVERY_MAGIC (0xf53bc0e7ad124589ULL)
@@ -119,7 +122,7 @@ typedef uint64_t tdb_off_t;
 	(sizeof(struct tdb_free_record) - sizeof(struct tdb_used_record))
 
 /* Indicates this entry is not on an flist (can happen during coalescing) */
-#define TDB_FLIST_NONE ((1ULL << TDB_OFF_UPPER_STEAL) - 1)
+#define TDB_FTABLE_NONE ((1ULL << TDB_OFF_UPPER_STEAL) - 1)
 
 #if !HAVE_BSWAP_64
 static inline uint64_t bswap_64(uint64_t x)
@@ -179,7 +182,7 @@ static inline uint16_t rec_magic(const struct tdb_used_record *r)
 
 struct tdb_free_record {
         uint64_t magic_and_prev; /* TDB_OFF_UPPER_STEAL bits magic, then prev */
-        uint64_t flist_and_len; /* Len not counting these two fields. */
+        uint64_t ftable_and_len; /* Len not counting these two fields. */
 	/* This is why the minimum record size is 8 bytes.  */
 	uint64_t next;
 };
@@ -196,12 +199,12 @@ static inline uint64_t frec_magic(const struct tdb_free_record *f)
 
 static inline uint64_t frec_len(const struct tdb_free_record *f)
 {
-	return f->flist_and_len & ((1ULL << (64 - TDB_OFF_UPPER_STEAL))-1);
+	return f->ftable_and_len & ((1ULL << (64 - TDB_OFF_UPPER_STEAL))-1);
 }
 
-static inline unsigned frec_flist(const struct tdb_free_record *f)
+static inline unsigned frec_ftable(const struct tdb_free_record *f)
 {
-	return f->flist_and_len >> (64 - TDB_OFF_UPPER_STEAL);
+	return f->ftable_and_len >> (64 - TDB_OFF_UPPER_STEAL);
 }
 
 struct tdb_recovery_record {
@@ -227,7 +230,7 @@ struct tdb_header {
 	uint64_t version; /* version of the code */
 	uint64_t hash_test; /* result of hashing HASH_MAGIC. */
 	uint64_t hash_seed; /* "random" seed written at creation time. */
-	tdb_off_t free_list; /* (First) free list. */
+	tdb_off_t free_table; /* (First) free table. */
 	tdb_off_t recovery; /* Transaction recovery area. */
 
 	tdb_off_t reserved[26];
@@ -236,7 +239,7 @@ struct tdb_header {
 	tdb_off_t hashtable[1ULL << TDB_TOPLEVEL_HASH_BITS];
 };
 
-struct tdb_freelist {
+struct tdb_freetable {
 	struct tdb_used_record hdr;
 	tdb_off_t next;
 	tdb_off_t buckets[TDB_FREE_BUCKETS];
@@ -339,9 +342,9 @@ struct tdb_context {
 	/* Set if we are in a transaction. */
 	struct tdb_transaction *transaction;
 	
-	/* What freelist are we using? */
-	uint64_t flist_off;
-	unsigned int flist;
+	/* What free table are we using? */
+	tdb_off_t ftable_off;
+	unsigned int ftable;
 
 	/* IO methods: changes for transactions. */
 	const struct tdb_methods *methods;
@@ -403,29 +406,29 @@ int delete_from_hash(struct tdb_context *tdb, struct hash_info *h);
 bool is_subhash(tdb_off_t val);
 
 /* free.c: */
-int tdb_flist_init(struct tdb_context *tdb);
+int tdb_ftable_init(struct tdb_context *tdb);
 
 /* check.c needs these to iterate through free lists. */
-tdb_off_t first_flist(struct tdb_context *tdb);
-tdb_off_t next_flist(struct tdb_context *tdb, tdb_off_t flist);
+tdb_off_t first_ftable(struct tdb_context *tdb);
+tdb_off_t next_ftable(struct tdb_context *tdb, tdb_off_t ftable);
 
-/* If this fails, try tdb_expand. */
+/* This returns space or TDB_OFF_ERR. */
 tdb_off_t alloc(struct tdb_context *tdb, size_t keylen, size_t datalen,
-		uint64_t hash, bool growing);
+		uint64_t hash, unsigned magic, bool growing);
 
 /* Put this record in a free list. */
 int add_free_record(struct tdb_context *tdb,
 		    tdb_off_t off, tdb_len_t len_with_header);
 
-/* Set up header for a used record. */
-int set_used_header(struct tdb_context *tdb,
-		    struct tdb_used_record *rec,
-		    uint64_t keylen, uint64_t datalen,
-		    uint64_t actuallen, unsigned hashlow);
+/* Set up header for a used/ftable/htable/chain record. */
+int set_header(struct tdb_context *tdb,
+	       struct tdb_used_record *rec,
+	       unsigned magic, uint64_t keylen, uint64_t datalen,
+	       uint64_t actuallen, unsigned hashlow);
 
 /* Used by tdb_check to verify. */
 unsigned int size_to_bucket(tdb_len_t data_len);
-tdb_off_t bucket_off(tdb_off_t flist_off, unsigned bucket);
+tdb_off_t bucket_off(tdb_off_t ftable_off, unsigned bucket);
 
 /* Used by tdb_summary */
 size_t dead_space(struct tdb_context *tdb, tdb_off_t off);
diff --git a/ccan/tdb2/summary.c b/ccan/tdb2/summary.c
index a03b0486..56d36588 100644
--- a/ccan/tdb2/summary.c
+++ b/ccan/tdb2/summary.c
@@ -37,7 +37,7 @@ static int count_hash(struct tdb_context *tdb,
 
 static bool summarize(struct tdb_context *tdb,
 		      struct tally *hashes,
-		      struct tally *flists,
+		      struct tally *ftables,
 		      struct tally *free,
 		      struct tally *keys,
 		      struct tally *data,
@@ -73,7 +73,7 @@ static bool summarize(struct tdb_context *tdb,
 			tally_add(buckets, size_to_bucket(len));
 			len += sizeof(p->u);
 			unc++;
-		} else if (rec_magic(&p->u) == TDB_MAGIC) {
+		} else if (rec_magic(&p->u) == TDB_USED_MAGIC) {
 			if (unc) {
 				tally_add(uncoal, unc);
 				unc = 0;
@@ -83,25 +83,31 @@ static bool summarize(struct tdb_context *tdb,
 				+ rec_data_length(&p->u)
 				+ rec_extra_padding(&p->u);
 
-			/* FIXME: Use different magic for hashes, flists. */
-			if (!rec_key_length(&p->u) && rec_hash(&p->u) < 3) {
-				if (rec_hash(&p->u) == 0) {
-					int count = count_hash(tdb,
-							off + sizeof(p->u),
-							TDB_SUBLEVEL_HASH_BITS);
-					if (count == -1)
-						return false;
-					tally_add(hashes, count);
-				} else if (rec_hash(&p->u) == 1) {
-					tally_add(flists,
-						  rec_data_length(&p->u));
-				} else if (rec_hash(&p->u) == 2) {
-					tally_add(chains, 1);
-				}
-			} else {
-				tally_add(keys, rec_key_length(&p->u));
-				tally_add(data, rec_data_length(&p->u));
-			}
+			tally_add(keys, rec_key_length(&p->u));
+			tally_add(data, rec_data_length(&p->u));
+			tally_add(extra, rec_extra_padding(&p->u));
+		} else if (rec_magic(&p->u) == TDB_HTABLE_MAGIC) {
+			int count = count_hash(tdb,
+					       off + sizeof(p->u),
+					       TDB_SUBLEVEL_HASH_BITS);
+			if (count == -1)
+				return false;
+			tally_add(hashes, count);
+			tally_add(extra, rec_extra_padding(&p->u));
+			len = sizeof(p->u)
+				+ rec_data_length(&p->u)
+				+ rec_extra_padding(&p->u);
+		} else if (rec_magic(&p->u) == TDB_FTABLE_MAGIC) {
+			len = sizeof(p->u)
+				+ rec_data_length(&p->u)
+				+ rec_extra_padding(&p->u);
+			tally_add(ftables, rec_data_length(&p->u));
+			tally_add(extra, rec_extra_padding(&p->u));
+		} else if (rec_magic(&p->u) == TDB_CHAIN_MAGIC) {
+			len = sizeof(p->u)
+				+ rec_data_length(&p->u)
+				+ rec_extra_padding(&p->u);
+			tally_add(chains, 1);
 			tally_add(extra, rec_extra_padding(&p->u));
 		} else
 			len = dead_space(tdb, off);
@@ -142,7 +148,7 @@ static bool summarize(struct tdb_context *tdb,
 char *tdb_summary(struct tdb_context *tdb, enum tdb_summary_flags flags)
 {
 	tdb_len_t len;
-	struct tally *flists, *hashes, *freet, *keys, *data, *extra, *uncoal,
+	struct tally *ftables, *hashes, *freet, *keys, *data, *extra, *uncoal,
 		*buckets, *chains;
 	char *hashesg, *freeg, *keysg, *datag, *extrag, *uncoalg, *bucketsg;
 	char *ret = NULL;
@@ -158,7 +164,7 @@ char *tdb_summary(struct tdb_context *tdb, enum tdb_summary_flags flags)
 	}
 
 	/* Start stats off empty. */
-	flists = tally_new(HISTO_HEIGHT);
+	ftables = tally_new(HISTO_HEIGHT);
 	hashes = tally_new(HISTO_HEIGHT);
 	freet = tally_new(HISTO_HEIGHT);
 	keys = tally_new(HISTO_HEIGHT);
@@ -167,14 +173,14 @@ char *tdb_summary(struct tdb_context *tdb, enum tdb_summary_flags flags)
 	uncoal = tally_new(HISTO_HEIGHT);
 	buckets = tally_new(HISTO_HEIGHT);
 	chains = tally_new(HISTO_HEIGHT);
-	if (!flists || !hashes || !freet || !keys || !data || !extra
+	if (!ftables || !hashes || !freet || !keys || !data || !extra
 	    || !uncoal || !buckets || !chains) {
 		tdb_logerr(tdb, TDB_ERR_OOM, TDB_DEBUG_ERROR,
 			   "tdb_summary: failed to allocate tally structures");
 		goto unlock;
 	}
 
-	if (!summarize(tdb, hashes, flists, freet, keys, data, extra, uncoal,
+	if (!summarize(tdb, hashes, ftables, freet, keys, data, extra, uncoal,
 		       buckets, chains))
 		goto unlock;
 
@@ -233,7 +239,7 @@ char *tdb_summary(struct tdb_context *tdb, enum tdb_summary_flags flags)
 		      tally_total(freet, NULL) * 100.0 / tdb->map_size,
 		      (tally_num(keys) + tally_num(freet) + tally_num(hashes))
 		      * sizeof(struct tdb_used_record) * 100.0 / tdb->map_size,
-		      tally_num(flists) * sizeof(struct tdb_freelist)
+		      tally_num(ftables) * sizeof(struct tdb_freetable)
 		      * 100.0 / tdb->map_size,
 		      (tally_num(hashes)
 		       * (sizeof(tdb_off_t) << TDB_SUBLEVEL_HASH_BITS)
@@ -256,6 +262,7 @@ unlock:
 	free(data);
 	free(extra);
 	free(uncoal);
+	free(ftables);
 	free(chains);
 
 	tdb_allrecord_unlock(tdb, F_RDLCK);
diff --git a/ccan/tdb2/tdb.c b/ccan/tdb2/tdb.c
index 9075fb91..dfa68451 100644
--- a/ccan/tdb2/tdb.c
+++ b/ccan/tdb2/tdb.c
@@ -72,7 +72,7 @@ static uint64_t random_number(struct tdb_context *tdb)
 
 struct new_database {
 	struct tdb_header hdr;
-	struct tdb_freelist flist;
+	struct tdb_freetable ftable;
 };
 
 /* initialise a new database */
@@ -101,11 +101,11 @@ static int tdb_new_database(struct tdb_context *tdb,
 	memset(newdb.hdr.hashtable, 0, sizeof(newdb.hdr.hashtable));
 
 	/* Free is empty. */
-	newdb.hdr.free_list = offsetof(struct new_database, flist);
-	memset(&newdb.flist, 0, sizeof(newdb.flist));
-	set_used_header(NULL, &newdb.flist.hdr, 0,
-			sizeof(newdb.flist) - sizeof(newdb.flist.hdr),
-			sizeof(newdb.flist) - sizeof(newdb.flist.hdr), 1);
+	newdb.hdr.free_table = offsetof(struct new_database, ftable);
+	memset(&newdb.ftable, 0, sizeof(newdb.ftable));
+	set_header(NULL, &newdb.ftable.hdr, TDB_FTABLE_MAGIC, 0,
+		   sizeof(newdb.ftable) - sizeof(newdb.ftable.hdr),
+		   sizeof(newdb.ftable) - sizeof(newdb.ftable.hdr), 0);
 
 	/* Magic food */
 	memset(newdb.hdr.magic_food, 0, sizeof(newdb.hdr.magic_food));
@@ -229,7 +229,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 		}
 		tdb_convert(tdb, &hdr.hash_seed, sizeof(hdr.hash_seed));
 		tdb->hash_seed = hdr.hash_seed;
-		tdb_flist_init(tdb);
+		tdb_ftable_init(tdb);
 		return tdb;
 	}
 
@@ -324,7 +324,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 		goto fail;
 	}
 
-	if (tdb_flist_init(tdb) == -1)
+	if (tdb_ftable_init(tdb) == -1)
 		goto fail;
 
 	tdb->next = tdbs;
@@ -386,7 +386,8 @@ static int update_rec_hdr(struct tdb_context *tdb,
 {
 	uint64_t dataroom = rec_data_length(rec) + rec_extra_padding(rec);
 
-	if (set_used_header(tdb, rec, keylen, datalen, keylen + dataroom, h))
+	if (set_header(tdb, rec, TDB_USED_MAGIC, keylen, datalen,
+		       keylen + dataroom, h))
 		return -1;
 
 	return tdb_write_convert(tdb, off, rec, sizeof(*rec));
@@ -402,7 +403,8 @@ static int replace_data(struct tdb_context *tdb,
 	tdb_off_t new_off;
 
 	/* Allocate a new record. */
-	new_off = alloc(tdb, key.dsize, dbuf.dsize, h->h, growing);
+	new_off = alloc(tdb, key.dsize, dbuf.dsize, h->h, TDB_USED_MAGIC,
+			growing);
 	if (unlikely(new_off == TDB_OFF_ERR))
 		return -1;
 
diff --git a/ccan/tdb2/test/layout.c b/ccan/tdb2/test/layout.c
index 25f41e25..d4f68cbf 100644
--- a/ccan/tdb2/test/layout.c
+++ b/ccan/tdb2/test/layout.c
@@ -23,20 +23,20 @@ static void add(struct tdb_layout *layout, union tdb_layout_elem elem)
 	layout->elem[layout->num_elems++] = elem;
 }
 
-void tdb_layout_add_freelist(struct tdb_layout *layout)
+void tdb_layout_add_freetable(struct tdb_layout *layout)
 {
 	union tdb_layout_elem elem;
-	elem.base.type = FREELIST;
+	elem.base.type = FREETABLE;
 	add(layout, elem);
 }
 
 void tdb_layout_add_free(struct tdb_layout *layout, tdb_len_t len,
-			 unsigned flist)
+			 unsigned ftable)
 {
 	union tdb_layout_elem elem;
 	elem.base.type = FREE;
 	elem.free.len = len;
-	elem.free.flist_num = flist;
+	elem.free.ftable_num = ftable;
 	add(layout, elem);
 }
 
@@ -82,9 +82,9 @@ static tdb_len_t hashtable_len(struct tle_hashtable *htable)
 		+ htable->extra;
 }
 
-static tdb_len_t freelist_len(struct tle_freelist *flist)
+static tdb_len_t freetable_len(struct tle_freetable *ftable)
 {
-	return sizeof(struct tdb_freelist);
+	return sizeof(struct tdb_freetable);
 }
 
 static void set_free_record(void *mem, tdb_len_t len)
@@ -97,9 +97,9 @@ static void set_data_record(void *mem, struct tdb_context *tdb,
 {
 	struct tdb_used_record *u = mem;
 
-	set_used_header(tdb, u, used->key.dsize, used->data.dsize,
-			used->key.dsize + used->data.dsize + used->extra,
-			tdb_hash(tdb, used->key.dptr, used->key.dsize));
+	set_header(tdb, u, TDB_USED_MAGIC, used->key.dsize, used->data.dsize,
+		   used->key.dsize + used->data.dsize + used->extra,
+		   tdb_hash(tdb, used->key.dptr, used->key.dsize));
 	memcpy(u + 1, used->key.dptr, used->key.dsize);
 	memcpy((char *)(u + 1) + used->key.dsize,
 	       used->data.dptr, used->data.dsize);
@@ -111,36 +111,36 @@ static void set_hashtable(void *mem, struct tdb_context *tdb,
 	struct tdb_used_record *u = mem;
 	tdb_len_t len = sizeof(tdb_off_t) << TDB_SUBLEVEL_HASH_BITS;
 
-	set_used_header(tdb, u, 0, len, len + htable->extra, 0);
+	set_header(tdb, u, TDB_HTABLE_MAGIC, 0, len, len + htable->extra, 0);
 	memset(u + 1, 0, len);
 }
 
-static void set_freelist(void *mem, struct tdb_context *tdb,
-			 struct tle_freelist *freelist, struct tdb_header *hdr,
-			 tdb_off_t last_flist)
+static void set_freetable(void *mem, struct tdb_context *tdb,
+			 struct tle_freetable *freetable, struct tdb_header *hdr,
+			 tdb_off_t last_ftable)
 {
-	struct tdb_freelist *flist = mem;
-	memset(flist, 0, sizeof(*flist));
-	set_used_header(tdb, &flist->hdr, 0,
-			sizeof(*flist) - sizeof(flist->hdr),
-			sizeof(*flist) - sizeof(flist->hdr), 1);
-
-	if (last_flist) {
-		flist = (struct tdb_freelist *)((char *)hdr + last_flist);
-		flist->next = freelist->base.off;
+	struct tdb_freetable *ftable = mem;
+	memset(ftable, 0, sizeof(*ftable));
+	set_header(tdb, &ftable->hdr, TDB_FTABLE_MAGIC, 0,
+			sizeof(*ftable) - sizeof(ftable->hdr),
+			sizeof(*ftable) - sizeof(ftable->hdr), 0);
+
+	if (last_ftable) {
+		ftable = (struct tdb_freetable *)((char *)hdr + last_ftable);
+		ftable->next = freetable->base.off;
 	} else {
-		hdr->free_list = freelist->base.off;
+		hdr->free_table = freetable->base.off;
 	}
 }
 
 static void add_to_freetable(struct tdb_context *tdb,
 			     tdb_off_t eoff,
 			     tdb_off_t elen,
-			     unsigned flist,
-			     struct tle_freelist *freelist)
+			     unsigned ftable,
+			     struct tle_freetable *freetable)
 {
-	tdb->flist_off = freelist->base.off;
-	tdb->flist = flist;
+	tdb->ftable_off = freetable->base.off;
+	tdb->ftable = ftable;
 	add_free_record(tdb, eoff, sizeof(struct tdb_used_record) + elen);
 }
 
@@ -204,15 +204,15 @@ static void add_to_hashtable(struct tdb_context *tdb,
 	abort();
 }
 
-static struct tle_freelist *find_flist(struct tdb_layout *layout, unsigned num)
+static struct tle_freetable *find_ftable(struct tdb_layout *layout, unsigned num)
 {
 	unsigned i;
 
 	for (i = 0; i < layout->num_elems; i++) {
-		if (layout->elem[i].base.type != FREELIST)
+		if (layout->elem[i].base.type != FREETABLE)
 			continue;
 		if (num == 0)
-			return &layout->elem[i].flist;
+			return &layout->elem[i].ftable;
 		num--;
 	}
 	abort();
@@ -222,7 +222,7 @@ static struct tle_freelist *find_flist(struct tdb_layout *layout, unsigned num)
 struct tdb_context *tdb_layout_get(struct tdb_layout *layout)
 {
 	unsigned int i;
-	tdb_off_t off, len, last_flist;
+	tdb_off_t off, len, last_ftable;
 	char *mem;
 	struct tdb_context *tdb;
 
@@ -233,8 +233,8 @@ struct tdb_context *tdb_layout_get(struct tdb_layout *layout)
 		union tdb_layout_elem *e = &layout->elem[i];
 		e->base.off = off;
 		switch (e->base.type) {
-		case FREELIST:
-			len = freelist_len(&e->flist);
+		case FREETABLE:
+			len = freetable_len(&e->ftable);
 			break;
 		case FREE:
 			len = free_record_len(e->free.len);
@@ -261,14 +261,14 @@ struct tdb_context *tdb_layout_get(struct tdb_layout *layout)
 	tdb->map_ptr = mem;
 	tdb->map_size = off;
 
-	last_flist = 0;
+	last_ftable = 0;
 	for (i = 0; i < layout->num_elems; i++) {
 		union tdb_layout_elem *e = &layout->elem[i];
 		switch (e->base.type) {
-		case FREELIST:
-			set_freelist(mem + e->base.off, tdb, &e->flist,
-				     (struct tdb_header *)mem, last_flist);
-			last_flist = e->base.off;
+		case FREETABLE:
+			set_freetable(mem + e->base.off, tdb, &e->ftable,
+				     (struct tdb_header *)mem, last_ftable);
+			last_ftable = e->base.off;
 			break;
 		case FREE:
 			set_free_record(mem + e->base.off, e->free.len);
@@ -281,8 +281,8 @@ struct tdb_context *tdb_layout_get(struct tdb_layout *layout)
 			break;
 		}
 	}
-	/* Must have a free list! */
-	assert(last_flist);
+	/* Must have a free table! */
+	assert(last_ftable);
 
 	/* Now fill the free and hash tables. */
 	for (i = 0; i < layout->num_elems; i++) {
@@ -290,8 +290,8 @@ struct tdb_context *tdb_layout_get(struct tdb_layout *layout)
 		switch (e->base.type) {
 		case FREE:
 			add_to_freetable(tdb, e->base.off, e->free.len,
-					 e->free.flist_num,
-					 find_flist(layout, e->free.flist_num));
+					 e->free.ftable_num,
+					 find_ftable(layout, e->free.ftable_num));
 			break;
 		case DATA:
 			add_to_hashtable(tdb, e->base.off, e->used.key);
@@ -301,7 +301,7 @@ struct tdb_context *tdb_layout_get(struct tdb_layout *layout)
 		}
 	}
 
-	tdb->flist_off = find_flist(layout, 0)->base.off;
+	tdb->ftable_off = find_ftable(layout, 0)->base.off;
 
 	/* Get physical if they asked for it. */
 	if (layout->filename) {
diff --git a/ccan/tdb2/test/layout.h b/ccan/tdb2/test/layout.h
index 2060db86..083deb47 100644
--- a/ccan/tdb2/test/layout.h
+++ b/ccan/tdb2/test/layout.h
@@ -3,9 +3,9 @@
 #include <ccan/tdb2/private.h>
 
 struct tdb_layout *new_tdb_layout(const char *filename);
-void tdb_layout_add_freelist(struct tdb_layout *layout);
+void tdb_layout_add_freetable(struct tdb_layout *layout);
 void tdb_layout_add_free(struct tdb_layout *layout, tdb_len_t len,
-			 unsigned flist);
+			 unsigned ftable);
 void tdb_layout_add_used(struct tdb_layout *layout,
 			 TDB_DATA key, TDB_DATA data,
 			 tdb_len_t extra);
@@ -18,7 +18,7 @@ void tdb_layout_add_hashtable(struct tdb_layout *layout,
 struct tdb_context *tdb_layout_get(struct tdb_layout *layout);
 
 enum layout_type {
-	FREELIST, FREE, DATA, HASHTABLE,
+	FREETABLE, FREE, DATA, HASHTABLE,
 };
 
 /* Shared by all union members. */
@@ -27,14 +27,14 @@ struct tle_base {
 	tdb_off_t off;
 };
 
-struct tle_freelist {
+struct tle_freetable {
 	struct tle_base base;
 };
 
 struct tle_free {
 	struct tle_base base;
 	tdb_len_t len;
-	unsigned flist_num;
+	unsigned ftable_num;
 };
 
 struct tle_used {
@@ -53,7 +53,7 @@ struct tle_hashtable {
 
 union tdb_layout_elem {
 	struct tle_base base;
-	struct tle_freelist flist;
+	struct tle_freetable ftable;
 	struct tle_free free;
 	struct tle_used used;
 	struct tle_hashtable hashtable;
diff --git a/ccan/tdb2/test/run-001-encode.c b/ccan/tdb2/test/run-001-encode.c
index 3a49fbbf..0c8ab61e 100644
--- a/ccan/tdb2/test/run-001-encode.c
+++ b/ccan/tdb2/test/run-001-encode.c
@@ -18,14 +18,14 @@ int main(int argc, char *argv[])
 
 	/* We should be able to encode any data value. */
 	for (i = 0; i < 64; i++)
-		ok1(set_used_header(&tdb, &rec, 0, 1ULL << i, 1ULL << i, 0)
-		    == 0);
+		ok1(set_header(&tdb, &rec, TDB_USED_MAGIC, 0, 1ULL << i,
+			       1ULL << i, 0) == 0);
 
 	/* And any key and data with < 64 bits between them. */
 	for (i = 0; i < 32; i++) {
 		tdb_len_t dlen = 1ULL >> (63 - i), klen = 1ULL << i;
-		ok1(set_used_header(&tdb, &rec, klen, dlen, klen + dlen, 0)
-		    == 0);
+		ok1(set_header(&tdb, &rec, TDB_USED_MAGIC, klen, dlen,
+			       klen + dlen, 0)  == 0);
 	}
 
 	/* We should neatly encode all values. */
@@ -34,13 +34,13 @@ int main(int argc, char *argv[])
 		uint64_t klen = 1ULL << (i < 16 ? i : 15);
 		uint64_t dlen = 1ULL << i;
 		uint64_t xlen = 1ULL << (i < 32 ? i : 31);
-		ok1(set_used_header(&tdb, &rec, klen, dlen, klen+dlen+xlen, h)
-		    == 0);
+		ok1(set_header(&tdb, &rec, TDB_USED_MAGIC, klen, dlen,
+			       klen+dlen+xlen, h) == 0);
 		ok1(rec_key_length(&rec) == klen);
 		ok1(rec_data_length(&rec) == dlen);
 		ok1(rec_extra_padding(&rec) == xlen);
 		ok1((uint64_t)rec_hash(&rec) == h);
-		ok1(rec_magic(&rec) == TDB_MAGIC);
+		ok1(rec_magic(&rec) == TDB_USED_MAGIC);
 	}
 	ok1(tap_log_messages == 0);
 	return exit_status();
diff --git a/ccan/tdb2/test/run-03-coalesce.c b/ccan/tdb2/test/run-03-coalesce.c
index 4def490f..a382ae08 100644
--- a/ccan/tdb2/test/run-03-coalesce.c
+++ b/ccan/tdb2/test/run-03-coalesce.c
@@ -38,7 +38,7 @@ int main(int argc, char *argv[])
 
 	/* No coalescing can be done due to EOF */
 	layout = new_tdb_layout(NULL);
-	tdb_layout_add_freelist(layout);
+	tdb_layout_add_freetable(layout);
 	len = 1024;
 	tdb_layout_add_free(layout, len, 0);
 	tdb = tdb_layout_get(layout);
@@ -46,7 +46,7 @@ int main(int argc, char *argv[])
 	ok1(free_record_length(tdb, layout->elem[1].base.off) == len);
 
 	/* Figure out which bucket free entry is. */
-	b_off = bucket_off(tdb->flist_off, size_to_bucket(len));
+	b_off = bucket_off(tdb->ftable_off, size_to_bucket(len));
 	/* Lock and fail to coalesce. */
 	ok1(tdb_lock_free_bucket(tdb, b_off, TDB_LOCK_WAIT) == 0);
 	ok1(coalesce(tdb, layout->elem[1].base.off, b_off, len) == 0);
@@ -57,7 +57,7 @@ int main(int argc, char *argv[])
 
 	/* No coalescing can be done due to used record */
 	layout = new_tdb_layout(NULL);
-	tdb_layout_add_freelist(layout);
+	tdb_layout_add_freetable(layout);
 	tdb_layout_add_free(layout, 1024, 0);
 	tdb_layout_add_used(layout, key, data, 6);
 	tdb = tdb_layout_get(layout);
@@ -65,7 +65,7 @@ int main(int argc, char *argv[])
 	ok1(tdb_check(tdb, NULL, NULL) == 0);
 
 	/* Figure out which bucket free entry is. */
-	b_off = bucket_off(tdb->flist_off, size_to_bucket(1024));
+	b_off = bucket_off(tdb->ftable_off, size_to_bucket(1024));
 	/* Lock and fail to coalesce. */
 	ok1(tdb_lock_free_bucket(tdb, b_off, TDB_LOCK_WAIT) == 0);
 	ok1(coalesce(tdb, layout->elem[1].base.off, b_off, 1024) == 0);
@@ -76,7 +76,7 @@ int main(int argc, char *argv[])
 
 	/* Coalescing can be done due to two free records, then EOF */
 	layout = new_tdb_layout(NULL);
-	tdb_layout_add_freelist(layout);
+	tdb_layout_add_freetable(layout);
 	tdb_layout_add_free(layout, 1024, 0);
 	tdb_layout_add_free(layout, 2048, 0);
 	tdb = tdb_layout_get(layout);
@@ -85,7 +85,7 @@ int main(int argc, char *argv[])
 	ok1(tdb_check(tdb, NULL, NULL) == 0);
 
 	/* Figure out which bucket (first) free entry is. */
-	b_off = bucket_off(tdb->flist_off, size_to_bucket(1024));
+	b_off = bucket_off(tdb->ftable_off, size_to_bucket(1024));
 	/* Lock and coalesce. */
 	ok1(tdb_lock_free_bucket(tdb, b_off, TDB_LOCK_WAIT) == 0);
 	ok1(coalesce(tdb, layout->elem[1].base.off, b_off, 1024) == 1);
@@ -97,7 +97,7 @@ int main(int argc, char *argv[])
 
 	/* Coalescing can be done due to two free records, then data */
 	layout = new_tdb_layout(NULL);
-	tdb_layout_add_freelist(layout);
+	tdb_layout_add_freetable(layout);
 	tdb_layout_add_free(layout, 1024, 0);
 	tdb_layout_add_free(layout, 512, 0);
 	tdb_layout_add_used(layout, key, data, 6);
@@ -107,7 +107,7 @@ int main(int argc, char *argv[])
 	ok1(tdb_check(tdb, NULL, NULL) == 0);
 
 	/* Figure out which bucket free entry is. */
-	b_off = bucket_off(tdb->flist_off, size_to_bucket(1024));
+	b_off = bucket_off(tdb->ftable_off, size_to_bucket(1024));
 	/* Lock and coalesce. */
 	ok1(tdb_lock_free_bucket(tdb, b_off, TDB_LOCK_WAIT) == 0);
 	ok1(coalesce(tdb, layout->elem[1].base.off, b_off, 1024) == 1);
@@ -119,7 +119,7 @@ int main(int argc, char *argv[])
 
 	/* Coalescing can be done due to three free records, then EOF */
 	layout = new_tdb_layout(NULL);
-	tdb_layout_add_freelist(layout);
+	tdb_layout_add_freetable(layout);
 	tdb_layout_add_free(layout, 1024, 0);
 	tdb_layout_add_free(layout, 512, 0);
 	tdb_layout_add_free(layout, 256, 0);
@@ -130,7 +130,7 @@ int main(int argc, char *argv[])
 	ok1(tdb_check(tdb, NULL, NULL) == 0);
 
 	/* Figure out which bucket free entry is. */
-	b_off = bucket_off(tdb->flist_off, size_to_bucket(1024));
+	b_off = bucket_off(tdb->ftable_off, size_to_bucket(1024));
 	/* Lock and coalesce. */
 	ok1(tdb_lock_free_bucket(tdb, b_off, TDB_LOCK_WAIT) == 0);
 	ok1(coalesce(tdb, layout->elem[1].base.off, b_off, 1024) == 1);
diff --git a/ccan/tdb2/test/run-04-basichash.c b/ccan/tdb2/test/run-04-basichash.c
index 491c853f..ceee0683 100644
--- a/ccan/tdb2/test/run-04-basichash.c
+++ b/ccan/tdb2/test/run-04-basichash.c
@@ -65,7 +65,8 @@ int main(int argc, char *argv[])
 		/* FIXME: Check lock length */
 
 		/* Allocate a new record. */
-		new_off = alloc(tdb, key.dsize, dbuf.dsize, h.h, false);
+		new_off = alloc(tdb, key.dsize, dbuf.dsize, h.h,
+				TDB_USED_MAGIC, false);
 		ok1(new_off != TDB_OFF_ERR);
 
 		/* We should be able to add it now. */
@@ -225,7 +226,8 @@ int main(int argc, char *argv[])
 
 		/* We should be able to add it now. */
 		/* Allocate a new record. */
-		new_off = alloc(tdb, key.dsize, dbuf.dsize, h.h, false);
+		new_off = alloc(tdb, key.dsize, dbuf.dsize, h.h,
+				TDB_USED_MAGIC, false);
 		ok1(new_off != TDB_OFF_ERR);
 		ok1(add_to_hash(tdb, &h, new_off) == 0);
 
diff --git a/ccan/tdb2/test/run-30-exhaust-before-expand.c b/ccan/tdb2/test/run-30-exhaust-before-expand.c
index 6ab81f85..ff749aac 100644
--- a/ccan/tdb2/test/run-30-exhaust-before-expand.c
+++ b/ccan/tdb2/test/run-30-exhaust-before-expand.c
@@ -9,13 +9,13 @@
 #include <err.h>
 #include "logging.h"
 
-static bool empty_freelist(struct tdb_context *tdb)
+static bool empty_freetable(struct tdb_context *tdb)
 {
-	struct tdb_freelist free;
+	struct tdb_freetable free;
 	unsigned int i;
 
-	/* Now, free list should be completely exhausted in zone 0 */
-	if (tdb_read_convert(tdb, tdb->flist_off, &free, sizeof(free)) != 0)
+	/* Now, free table should be completely exhausted in zone 0 */
+	if (tdb_read_convert(tdb, tdb->ftable_off, &free, sizeof(free)) != 0)
 		abort();
 
 	for (i = 0; i < sizeof(free.buckets)/sizeof(free.buckets[0]); i++) {
@@ -50,26 +50,26 @@ int main(int argc, char *argv[])
 		if (!tdb)
 			continue;
 
-		ok1(empty_freelist(tdb));
+		ok1(empty_freetable(tdb));
 		/* Need some hash lock for expand. */
 		ok1(tdb_lock_hashes(tdb, 0, 1, F_WRLCK, TDB_LOCK_WAIT) == 0);
 		/* Create some free space. */
 		ok1(tdb_expand(tdb, 1) == 0);
 		ok1(tdb_unlock_hashes(tdb, 0, 1, F_WRLCK) == 0);
 		ok1(tdb_check(tdb, NULL, NULL) == 0);
-		ok1(!empty_freelist(tdb));
+		ok1(!empty_freetable(tdb));
 
 		size = tdb->map_size;
 		/* Insert minimal-length records until we expand. */
 		for (j = 0; tdb->map_size == size; j++) {
-			was_empty = empty_freelist(tdb);
+			was_empty = empty_freetable(tdb);
 			if (tdb_store(tdb, k, k, TDB_INSERT) != 0)
 				err(1, "Failed to store record %i", j);
 		}
 
 		/* Would have been empty before expansion, but no longer. */
 		ok1(was_empty);
-		ok1(!empty_freelist(tdb));
+		ok1(!empty_freetable(tdb));
 		tdb_close(tdb);
 	}
 
diff --git a/ccan/tdb2/test/run-50-multiple-freelists.c b/ccan/tdb2/test/run-50-multiple-freelists.c
index fd709730..1e33eb1b 100644
--- a/ccan/tdb2/test/run-50-multiple-freelists.c
+++ b/ccan/tdb2/test/run-50-multiple-freelists.c
@@ -22,11 +22,11 @@ int main(int argc, char *argv[])
 	data.dsize = 5;
 	key.dsize = 5;
 
-	/* Create a TDB with three free lists. */
+	/* Create a TDB with three free tables. */
 	layout = new_tdb_layout(NULL);
-	tdb_layout_add_freelist(layout);
-	tdb_layout_add_freelist(layout);
-	tdb_layout_add_freelist(layout);
+	tdb_layout_add_freetable(layout);
+	tdb_layout_add_freetable(layout);
+	tdb_layout_add_freetable(layout);
 	tdb_layout_add_free(layout, 80, 0);
 	/* Used record prevent coalescing. */
 	tdb_layout_add_used(layout, key, data, 6);
@@ -40,24 +40,28 @@ int main(int argc, char *argv[])
 	tdb = tdb_layout_get(layout);
 	ok1(tdb_check(tdb, NULL, NULL) == 0);
 
-	off = get_free(tdb, 0, 80 - sizeof(struct tdb_used_record), 0, 0);
+	off = get_free(tdb, 0, 80 - sizeof(struct tdb_used_record), 0,
+		       TDB_USED_MAGIC, 0);
 	ok1(off == layout->elem[3].base.off);
-	ok1(tdb->flist_off == layout->elem[0].base.off);
+	ok1(tdb->ftable_off == layout->elem[0].base.off);
 
-	off = get_free(tdb, 0, 160 - sizeof(struct tdb_used_record), 0, 0);
+	off = get_free(tdb, 0, 160 - sizeof(struct tdb_used_record), 0,
+		       TDB_USED_MAGIC, 0);
 	ok1(off == layout->elem[5].base.off);
-	ok1(tdb->flist_off == layout->elem[1].base.off);
+	ok1(tdb->ftable_off == layout->elem[1].base.off);
 
-	off = get_free(tdb, 0, 320 - sizeof(struct tdb_used_record), 0, 0);
+	off = get_free(tdb, 0, 320 - sizeof(struct tdb_used_record), 0,
+		       TDB_USED_MAGIC, 0);
 	ok1(off == layout->elem[7].base.off);
-	ok1(tdb->flist_off == layout->elem[2].base.off);
+	ok1(tdb->ftable_off == layout->elem[2].base.off);
 
-	off = get_free(tdb, 0, 40 - sizeof(struct tdb_used_record), 0, 0);
+	off = get_free(tdb, 0, 40 - sizeof(struct tdb_used_record), 0,
+		       TDB_USED_MAGIC, 0);
 	ok1(off == layout->elem[9].base.off);
-	ok1(tdb->flist_off == layout->elem[0].base.off);
+	ok1(tdb->ftable_off == layout->elem[0].base.off);
 
 	/* Now we fail. */
-	off = get_free(tdb, 0, 0, 1, 0);
+	off = get_free(tdb, 0, 0, 1, TDB_USED_MAGIC, 0);
 	ok1(off == 0);
 
 	tdb_close(tdb);