X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Ffree.c;h=6fd82c5c540d0ee2767d60385c43654606396c8b;hp=2b07fdff330a3dfe23631dd6e98a3effb399e428;hb=dfae76fd82d4bbd8989264dadc2c3c9cde7e5af7;hpb=590eee6faf0d56ac4e7b60a51817d655bb3310cb

diff --git a/ccan/tdb2/free.c b/ccan/tdb2/free.c
index 2b07fdff..6fd82c5c 100644
--- a/ccan/tdb2/free.c
+++ b/ccan/tdb2/free.c
@@ -28,7 +28,7 @@ static unsigned fls64(uint64_t val)
 }
 
 /* In which bucket would we find a particular record size? (ignoring header) */
-unsigned int size_to_bucket(unsigned int zone_bits, tdb_len_t data_len)
+unsigned int size_to_bucket(tdb_len_t data_len)
 {
 	unsigned int bucket;
 
@@ -44,90 +44,59 @@ unsigned int size_to_bucket(unsigned int zone_bits, tdb_len_t data_len)
 		bucket = fls64(data_len - TDB_MIN_DATA_LEN) + 2;
 	}
 
-	if (unlikely(bucket > BUCKETS_FOR_ZONE(zone_bits)))
-		bucket = BUCKETS_FOR_ZONE(zone_bits);
+	if (unlikely(bucket >= TDB_FREE_BUCKETS))
+		bucket = TDB_FREE_BUCKETS - 1;
 	return bucket;
 }
 
-/* Subtract 1-byte tailer and header.  Then round up to next power of 2. */
-static unsigned max_zone_bits(struct tdb_context *tdb)
+tdb_off_t first_flist(struct tdb_context *tdb)
 {
-	return fls64(tdb->map_size-1-sizeof(struct tdb_header)-1) + 1;
+	return tdb_read_off(tdb, offsetof(struct tdb_header, free_list));
 }
 
-/* Start by using a random zone to spread the load: returns the offset. */
-static uint64_t random_zone(struct tdb_context *tdb)
+tdb_off_t next_flist(struct tdb_context *tdb, tdb_off_t flist)
 {
-	struct free_zone_header zhdr;
-	tdb_off_t off = sizeof(struct tdb_header);
-	tdb_len_t half_bits;
-	uint64_t randbits = 0;
-	unsigned int i;
-
-	for (i = 0; i < 64; i += fls64(RAND_MAX)) 
-		randbits ^= ((uint64_t)random()) << i;
-
-	/* FIXME: Does this work?  Test! */
-	half_bits = max_zone_bits(tdb) - 1;
-	do {
-		/* Pick left or right side (not outside file) */
-		if ((randbits & 1)
-		    && !tdb->methods->oob(tdb, off + (1ULL << half_bits)
-					  + sizeof(zhdr), true)) {
-			off += 1ULL << half_bits;
-		}
-		randbits >>= 1;
+	return tdb_read_off(tdb, flist + offsetof(struct tdb_freelist, next));
+}
 
-		if (tdb_read_convert(tdb, off, &zhdr, sizeof(zhdr)) == -1) 
-			return TDB_OFF_ERR;
+int tdb_flist_init(struct tdb_context *tdb)
+{
+	/* Use reservoir sampling algorithm to select a free list at random. */
+	unsigned int rnd, max = 0;
+	tdb_off_t off;
 
-		if (zhdr.zone_bits == half_bits)
-			return off;
+	tdb->flist_off = off = first_flist(tdb);
 
-		half_bits--;
-	} while (half_bits >= INITIAL_ZONE_BITS);
+	while (off) {
+		if (off == TDB_OFF_ERR)
+			return -1;
 
-	tdb->ecode = TDB_ERR_CORRUPT;
-	tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
-		 "random_zone: zone at %llu smaller than %u bits?",
-		 (long long)off, INITIAL_ZONE_BITS);
-	return TDB_OFF_ERR;
-}
+		rnd = random();
+		if (rnd >= max) {
+			tdb->flist_off = off;
+			max = rnd;
+		}
 
-int tdb_zone_init(struct tdb_context *tdb)
-{
-	tdb->zone_off = random_zone(tdb);
-	if (tdb->zone_off == TDB_OFF_ERR)
-		return -1;
-	if (tdb_read_convert(tdb, tdb->zone_off,
-			     &tdb->zhdr, sizeof(tdb->zhdr)) == -1) 
-		return -1;
+		off = next_flist(tdb, off);
+	}
 	return 0;
 }
 
-/* Where's the header, given a zone size of 1 << zone_bits? */
-static tdb_off_t zone_off(tdb_off_t off, unsigned int zone_bits)
-{
-	off -= sizeof(struct tdb_header);
-	return (off & ~((1ULL << zone_bits) - 1)) + sizeof(struct tdb_header);
-}
-
 /* Offset of a given bucket. */
-/* FIXME: bucket can be "unsigned" everywhere, or even uint8/16. */
-tdb_off_t bucket_off(tdb_off_t zone_off, tdb_off_t bucket)
+tdb_off_t bucket_off(tdb_off_t flist_off, unsigned bucket)
 {
-	return zone_off
-		+ sizeof(struct free_zone_header)
+	return flist_off + offsetof(struct tdb_freelist, 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 bucket)
+static tdb_off_t find_free_head(struct tdb_context *tdb,
+				tdb_off_t flist_off,
+				tdb_off_t bucket)
 {
 	/* Speculatively search for a non-zero bucket. */
-	return tdb_find_nonzero_off(tdb, bucket_off(tdb->zone_off, 0),
-				    bucket,
-				    BUCKETS_FOR_ZONE(tdb->zhdr.zone_bits) + 1);
+	return tdb_find_nonzero_off(tdb, bucket_off(flist_off, 0),
+				    bucket, TDB_FREE_BUCKETS);
 }
 
 /* Remove from free bucket. */
@@ -217,7 +186,6 @@ static int enqueue_in_free(struct tdb_context *tdb,
 
 /* List need not be locked. */
 int add_free_record(struct tdb_context *tdb,
-		    unsigned int zone_bits,
 		    tdb_off_t off, tdb_len_t len_with_header)
 {
 	struct tdb_free_record new;
@@ -225,13 +193,12 @@ int add_free_record(struct tdb_context *tdb,
 	int ret;
 
 	assert(len_with_header >= sizeof(new));
-	assert(zone_bits < (1 << 6));
 
-	new.magic_and_meta = TDB_FREE_MAGIC | zone_bits;
+	new.magic_and_meta = TDB_FREE_MAGIC << (64 - TDB_OFF_UPPER_STEAL)
+		| tdb->flist_off;
 	new.data_len = len_with_header - sizeof(struct tdb_used_record);
 
-	b_off = bucket_off(zone_off(off, zone_bits),
-			   size_to_bucket(zone_bits, new.data_len));
+	b_off = bucket_off(tdb->flist_off, size_to_bucket(new.data_len));
 	if (tdb_lock_free_bucket(tdb, b_off, TDB_LOCK_WAIT) != 0)
 		return -1;
 
@@ -240,14 +207,10 @@ int add_free_record(struct tdb_context *tdb,
 	return ret;
 }
 
-static size_t adjust_size(size_t keylen, size_t datalen, bool want_extra)
+static size_t adjust_size(size_t keylen, size_t datalen)
 {
 	size_t size = keylen + datalen;
 
-	/* We want at least 50% growth for data. */
-	if (want_extra)
-		size += datalen/2;
-
 	if (size < TDB_MIN_DATA_LEN)
 		size = TDB_MIN_DATA_LEN;
 
@@ -256,40 +219,31 @@ static size_t adjust_size(size_t keylen, size_t datalen, bool want_extra)
 }
 
 /* If we have enough left over to be useful, split that off. */
-static int to_used_record(struct tdb_context *tdb,
-			  unsigned int zone_bits,
-			  tdb_off_t off,
-			  tdb_len_t needed,
-			  tdb_len_t total_len,
-			  tdb_len_t *actual)
+static size_t record_leftover(size_t keylen, size_t datalen,
+			      bool want_extra, size_t total_len)
 {
-	struct tdb_used_record used;
-	tdb_len_t leftover;
+	ssize_t leftover;
 
-	leftover = total_len - needed;
-	if (leftover < sizeof(struct tdb_free_record))
-		leftover = 0;
+	if (want_extra)
+		datalen += datalen / 2;
+	leftover = total_len - adjust_size(keylen, datalen);
 
-	*actual = total_len - leftover;
+	if (leftover < (ssize_t)sizeof(struct tdb_free_record))
+		return 0;
 
-	if (leftover) {
-		if (add_free_record(tdb, zone_bits,
-				    off + sizeof(used) + *actual,
-				    total_len - needed))
-			return -1;
-	}
-	return 0;
+	return leftover;
 }
 
 /* Note: we unlock the current bucket if we coalesce or fail. */
 static int coalesce(struct tdb_context *tdb,
-		    tdb_off_t zone_off, unsigned zone_bits,
 		    tdb_off_t off, tdb_off_t b_off, tdb_len_t data_len)
 {
 	struct tdb_free_record pad, *r;
-	tdb_off_t end = off + sizeof(struct tdb_used_record) + data_len;
+	tdb_off_t end;
 
-	while (end < (zone_off + (1ULL << zone_bits))) {
+	end = off + sizeof(struct tdb_used_record) + data_len;
+
+	while (end < tdb->map_size) {
 		tdb_off_t nb_off;
 
 		/* FIXME: do tdb_get here and below really win? */
@@ -300,8 +254,7 @@ static int coalesce(struct tdb_context *tdb,
 		if (frec_magic(r) != TDB_FREE_MAGIC)
 			break;
 
-		nb_off = bucket_off(zone_off,
-				    size_to_bucket(zone_bits, r->data_len));
+		nb_off = bucket_off(frec_flist(r), size_to_bucket(r->data_len));
 
 		/* We may be violating lock order here, so best effort. */
 		if (tdb_lock_free_bucket(tdb, nb_off, TDB_LOCK_NOWAIT) == -1)
@@ -319,6 +272,13 @@ static int coalesce(struct tdb_context *tdb,
 			break;
 		}
 
+		if (unlikely(bucket_off(frec_flist(r),
+					size_to_bucket(r->data_len))
+			     != nb_off)) {
+			tdb_unlock_free_bucket(tdb, nb_off);
+			break;
+		}
+
 		if (remove_from_list(tdb, nb_off, end, r) == -1) {
 			tdb_unlock_free_bucket(tdb, nb_off);
 			goto err;
@@ -348,10 +308,20 @@ static int coalesce(struct tdb_context *tdb,
 	if (remove_from_list(tdb, b_off, off, r) == -1)
 		goto err;
 
-	/* We have to drop this to avoid deadlocks. */
+	r = tdb_access_write(tdb, off, sizeof(*r), true);
+	if (!r)
+		goto err;
+
+	/* We have to drop this to avoid deadlocks, so make sure record
+	 * doesn't get coalesced by someone else! */
+	r->magic_and_meta = TDB_COALESCING_MAGIC << (64 - TDB_OFF_UPPER_STEAL);
+	r->data_len = end - off - sizeof(struct tdb_used_record);
+	if (tdb_access_commit(tdb, r) != 0)
+		goto err;
+
 	tdb_unlock_free_bucket(tdb, b_off);
 
-	if (add_free_record(tdb, zone_bits, off, end - off) == -1)
+	if (add_free_record(tdb, off, end - off) == -1)
 		return -1;
 	return 1;
 
@@ -363,22 +333,21 @@ 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 zone_off,
-				unsigned zone_bits,
+				tdb_off_t flist_off,
 				tdb_off_t bucket,
-				size_t size,
-				tdb_len_t *actual)
+				size_t keylen, size_t datalen,
+				bool want_extra,
+				unsigned hashlow)
 {
 	tdb_off_t off, b_off,best_off;
 	struct tdb_free_record pad, best = { 0 }, *r;
 	double multiplier;
+	size_t size = adjust_size(keylen, datalen);
 
 again:
-	b_off = bucket_off(zone_off, bucket);
+	b_off = bucket_off(flist_off, bucket);
 
-	/* FIXME: Try non-blocking wait first, to measure contention.
-	 * If we're contented, try switching zones, and don't enlarge zone
-	 * next time (we want more zones). */
+	/* FIXME: Try non-blocking wait first, to measure contention. */
 	/* Lock this bucket. */
 	if (tdb_lock_free_bucket(tdb, b_off, TDB_LOCK_WAIT) == -1) {
 		return TDB_OFF_ERR;
@@ -386,8 +355,12 @@ again:
 
 	best.data_len = -1ULL;
 	best_off = 0;
-	/* FIXME: Start with larger multiplier if we're growing. */
-	multiplier = 1.0;
+
+	/* Get slack if we're after extra. */
+	if (want_extra)
+		multiplier = 1.5;
+	else
+		multiplier = 1.0;
 
 	/* Walk the list to see if any are large enough, getting less fussy
 	 * as we go. */
@@ -414,13 +387,12 @@ again:
 		}
 
 		if (best.data_len < size * multiplier && best_off)
-			goto use_best;
+			break;
 
 		multiplier *= 1.01;
 
 		/* Since we're going slow anyway, try coalescing here. */
-		switch (coalesce(tdb, zone_off, zone_bits, off, b_off,
-				 r->data_len)) {
+		switch (coalesce(tdb, off, b_off, r->data_len)) {
 		case -1:
 			/* This has already unlocked on error. */
 			return -1;
@@ -433,15 +405,35 @@ again:
 
 	/* If we found anything at all, use it. */
 	if (best_off) {
-	use_best:
+		struct tdb_used_record rec;
+		size_t leftover;
+
 		/* We're happy with this size: take it. */
 		if (remove_from_list(tdb, b_off, best_off, &best) != 0)
 			goto unlock_err;
+
+		leftover = record_leftover(keylen, datalen, want_extra,
+					   best.data_len);
+
+		assert(keylen + datalen + leftover <= best.data_len);
+		/* 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,
+				    best.data_len - leftover,
+				    hashlow) != 0)
+			goto unlock_err;
+
+		if (tdb_write_convert(tdb, best_off, &rec, sizeof(rec)) != 0)
+			goto unlock_err;
+
 		tdb_unlock_free_bucket(tdb, b_off);
 
-		if (to_used_record(tdb, zone_bits, best_off, size,
-				   best.data_len, actual)) {
-			return -1;
+		if (leftover) {
+			if (add_free_record(tdb,
+					    best_off + sizeof(rec)
+					    + best.data_len - leftover,
+					    leftover))
+				return TDB_OFF_ERR;
 		}
 		return best_off;
 	}
@@ -454,77 +446,62 @@ unlock_err:
 	return TDB_OFF_ERR;
 }
 
-static bool next_zone(struct tdb_context *tdb)
+/* 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)
 {
-	tdb_off_t next = tdb->zone_off + (1ULL << tdb->zhdr.zone_bits);
-
-	/* We must have a header. */
-	if (tdb->methods->oob(tdb, next + sizeof(tdb->zhdr), true))
-		return false;
-
-	tdb->zone_off = next;
-	return tdb_read_convert(tdb, next, &tdb->zhdr, sizeof(tdb->zhdr)) == 0;
-}
-
-/* Offset returned is within current zone (which it may alter). */
-static tdb_off_t get_free(struct tdb_context *tdb, size_t size,
-			  tdb_len_t *actual)
-{
-	tdb_off_t start_zone = tdb->zone_off, off;
+	tdb_off_t off, flist;
+	unsigned start_b, b;
 	bool wrapped = false;
 
-	/* FIXME: If we don't get a hit in the first bucket we want,
-	 * try changing zones for next time.  That should help wear
-	 * zones evenly, so we don't need to search all of them before
-	 * expanding. */
-	while (!wrapped || tdb->zone_off != start_zone) {
-		tdb_off_t b;
-
-		/* Shortcut for really huge allocations... */
-		if ((size >> tdb->zhdr.zone_bits) != 0)
-			continue;
+	/* If they are growing, add 50% to get to higher bucket. */
+	if (want_extra)
+		start_b = size_to_bucket(adjust_size(keylen,
+						     datalen + datalen / 2));
+	else
+		start_b = size_to_bucket(adjust_size(keylen, datalen));
 
+	flist = tdb->flist_off;
+	while (!wrapped || flist != tdb->flist_off) {
 		/* Start at exact size bucket, and search up... */
-		b = size_to_bucket(tdb->zhdr.zone_bits, size);
-		for (b = find_free_head(tdb, b);
-		     b <= BUCKETS_FOR_ZONE(tdb->zhdr.zone_bits);
-		     b += find_free_head(tdb, b + 1)) {
+		for (b = find_free_head(tdb, flist, start_b);
+		     b < TDB_FREE_BUCKETS;
+		     b = find_free_head(tdb, flist, b + 1)) {
 			/* Try getting one from list. */
-			off = lock_and_alloc(tdb, tdb->zone_off,
-					     tdb->zhdr.zone_bits,
-					     b, size, actual);
+			off = lock_and_alloc(tdb, flist,
+					     b, keylen, datalen, want_extra,
+					     hashlow);
 			if (off == TDB_OFF_ERR)
 				return TDB_OFF_ERR;
-			if (off != 0)
+			if (off != 0) {
+				/* Worked?  Stay using this list. */
+				tdb->flist_off = flist;
 				return off;
+			}
 			/* Didn't work.  Try next bucket. */
 		}
 
-		/* Didn't work, try next zone, if it exists. */
-		if (!next_zone(tdb)) {
+		/* Hmm, try next list. */
+		flist = next_flist(tdb, flist);
+		if (flist == 0) {
 			wrapped = true;
-			tdb->zone_off = sizeof(struct tdb_header);
-			if (tdb_read_convert(tdb, tdb->zone_off,
-					     &tdb->zhdr, sizeof(tdb->zhdr))) {
-				return TDB_OFF_ERR;
-			}
+			flist = first_flist(tdb);
 		}
 	}
+
 	return 0;
 }
 
-int set_header(struct tdb_context *tdb,
-	       struct tdb_used_record *rec,
-	       uint64_t keylen, uint64_t datalen,
-	       uint64_t actuallen, uint64_t hash,
-	       unsigned int zone_bits)
+int set_used_header(struct tdb_context *tdb,
+		    struct tdb_used_record *rec,
+		    uint64_t keylen, uint64_t datalen,
+		    uint64_t actuallen, unsigned hashlow)
 {
 	uint64_t keybits = (fls64(keylen) + 1) / 2;
 
 	/* Use bottom bits of hash, so it's independent of hash table size. */
-	rec->magic_and_meta
-		= zone_bits
-		| ((hash & ((1 << 5)-1)) << 6)
+	rec->magic_and_meta = (hashlow & ((1 << 11)-1))
 		| ((actuallen - (keylen + datalen)) << 11)
 		| (keybits << 43)
 		| (TDB_MAGIC << 48);
@@ -544,33 +521,23 @@ int set_header(struct tdb_context *tdb,
 	return 0;
 }
 
-static bool zones_happy(struct tdb_context *tdb)
-{
-	/* FIXME: look at distribution of zones. */
-	return true;
-}
-
-/* Assume we want buckets up to the comfort factor. */
-static tdb_len_t overhead(unsigned int zone_bits)
-{
-	return sizeof(struct free_zone_header)
-		+ (BUCKETS_FOR_ZONE(zone_bits) + 1) * sizeof(tdb_off_t);
-}
-
-/* Expand the database (by adding a zone). */
+/* Expand the database. */
 static int tdb_expand(struct tdb_context *tdb, tdb_len_t size)
 {
 	uint64_t old_size;
-	tdb_off_t off;
-	uint8_t zone_bits;
-	unsigned int num_buckets;
 	tdb_len_t wanted;
-	struct free_zone_header zhdr;
-	bool enlarge_zone;
 
 	/* We need room for the record header too. */
 	wanted = sizeof(struct tdb_used_record) + size;
 
+	/* Need to hold a hash lock to expand DB: transactions rely on it. */
+	if (!(tdb->flags & TDB_NOLOCK)
+	    && !tdb->allrecord_lock.count && !tdb_has_hash_locks(tdb)) {
+		tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
+			 "tdb_expand: must hold lock during expand\n");
+		return -1;
+	}
+
 	/* Only one person can expand file at a time. */
 	if (tdb_lock_expand(tdb, F_WRLCK) != 0)
 		return -1;
@@ -578,70 +545,20 @@ static int tdb_expand(struct tdb_context *tdb, tdb_len_t size)
 	/* Someone else may have expanded the file, so retry. */
 	old_size = tdb->map_size;
 	tdb->methods->oob(tdb, tdb->map_size + 1, true);
-	if (tdb->map_size != old_size)
-		goto success;
-
-	/* FIXME: Tailer is a bogus optimization, remove it. */
-	/* zone bits tailer char is protected by EXPAND lock. */
-	if (tdb->methods->read(tdb, old_size - 1, &zone_bits, 1) == -1)
-		goto fail;
-
-	/* If zones aren't working well, add larger zone if possible. */
-	enlarge_zone = !zones_happy(tdb);
-
-	/* New zone can be between zone_bits or larger if we're on the right
-	 * boundary. */
-	for (;;) {
-		/* Does this fit the allocation comfortably? */
-		if ((1ULL << zone_bits) >= overhead(zone_bits) + wanted) {
-			/* Only let enlarge_zone enlarge us once. */
-			if (!enlarge_zone)
-				break;
-			enlarge_zone = false;
-		}
-		if ((old_size - 1 - sizeof(struct tdb_header))
-		    & (1 << zone_bits))
-			break;
-		zone_bits++;
+	if (tdb->map_size != old_size) {
+		tdb_unlock_expand(tdb, F_WRLCK);
+		return 0;
 	}
 
-	zhdr.zone_bits = zone_bits;
-	num_buckets = BUCKETS_FOR_ZONE(zone_bits);
-
-	/* FIXME: I don't think we need to expand to full zone, do we? */
-	if (tdb->methods->expand_file(tdb, 1ULL << zone_bits) == -1)
-		goto fail;
-
-	/* Write new tailer. */
-	if (tdb->methods->write(tdb, tdb->map_size - 1, &zone_bits, 1) == -1)
-		goto fail;
-
-	/* Write new zone header (just before old tailer). */
-	off = old_size - 1;
-	if (tdb_write_convert(tdb, off, &zhdr, sizeof(zhdr)) == -1)
-		goto fail;
-
-	/* Now write empty buckets. */
-	off += sizeof(zhdr);
-	if (zero_out(tdb, off, (num_buckets+1) * sizeof(tdb_off_t)) == -1)
-		goto fail;
-	off += (num_buckets+1) * sizeof(tdb_off_t);
-
-	/* Now add the rest as our free record. */
-	if (add_free_record(tdb, zone_bits, off, tdb->map_size-1-off) == -1)
-		goto fail;
-
-	/* Try allocating from this zone now. */
-	tdb->zone_off = old_size - 1;
-	tdb->zhdr = zhdr;
+	if (tdb->methods->expand_file(tdb, wanted*TDB_EXTENSION_FACTOR) == -1) {
+		tdb_unlock_expand(tdb, F_WRLCK);
+		return -1;
+	}
 
-success:
+	/* We need to drop this lock before adding free record. */
 	tdb_unlock_expand(tdb, F_WRLCK);
-	return 0;
 
-fail:
-	tdb_unlock_expand(tdb, F_WRLCK);
-	return -1;
+	return add_free_record(tdb, old_size, wanted * TDB_EXTENSION_FACTOR);
 }
 
 /* This won't fail: it will expand the database if it has to. */
@@ -649,36 +566,18 @@ tdb_off_t alloc(struct tdb_context *tdb, size_t keylen, size_t datalen,
 		uint64_t hash, bool growing)
 {
 	tdb_off_t off;
-	tdb_len_t size, actual;
-	struct tdb_used_record rec;
 
 	/* We can't hold pointers during this: we could unmap! */
 	assert(!tdb->direct_access);
 
-	size = adjust_size(keylen, datalen, growing);
-
-again:
-	off = get_free(tdb, size, &actual);
-	if (unlikely(off == TDB_OFF_ERR))
-		return off;
+	for (;;) {
+		off = get_free(tdb, keylen, datalen, growing, hash);
+		if (likely(off != 0))
+			break;
 
-	if (unlikely(off == 0)) {
-		if (tdb_expand(tdb, size) == -1)
+		if (tdb_expand(tdb, adjust_size(keylen, datalen)))
 			return TDB_OFF_ERR;
-		goto again;
 	}
 
-	/* Some supergiant values can't be encoded. */
-	/* FIXME: Check before, and limit actual in get_free. */
-	if (set_header(tdb, &rec, keylen, datalen, actual, hash,
-		       tdb->zhdr.zone_bits) != 0) {
-		add_free_record(tdb, tdb->zhdr.zone_bits, off,
-				sizeof(rec) + actual);
-		return TDB_OFF_ERR;
-	}
-
-	if (tdb_write_convert(tdb, off, &rec, sizeof(rec)) != 0)
-		return TDB_OFF_ERR;
-	
 	return off;
 }