X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Ffree.c;h=7ede24616efc78df4e16eda260ace518bbd88755;hp=816d0ee540b3fe81f9fa2f8c4f40561442aab732;hb=40bab4d5df030f84a63d9c6cb1348d8f27442a0a;hpb=fe55330a60e4e14ea6cac2ff40d50eddca4cf140

diff --git a/ccan/tdb2/free.c b/ccan/tdb2/free.c
index 816d0ee5..7ede2461 100644
--- a/ccan/tdb2/free.c
+++ b/ccan/tdb2/free.c
@@ -1,7 +1,7 @@
- /* 
+ /*
    Trivial Database 2: free list/block handling
    Copyright (C) Rusty Russell 2010
-   
+
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
@@ -49,65 +49,67 @@ 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)
+enum TDB_ERROR 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)
-			return -1;
+		if (TDB_OFF_IS_ERR(off)) {
+			return off;
+		}
 
 		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;
+	return TDB_SUCCESS;
 }
 
 /* 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. */
+/* Returns free_buckets + 1, or list number to search, or -ve error. */
 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);
 }
 
 /* Remove from free bucket. */
-static int remove_from_list(struct tdb_context *tdb,
-			    tdb_off_t b_off, tdb_off_t r_off,
-			    struct tdb_free_record *r)
+static enum TDB_ERROR remove_from_list(struct tdb_context *tdb,
+				       tdb_off_t b_off, tdb_off_t r_off,
+				       const struct tdb_free_record *r)
 {
 	tdb_off_t off;
+	enum TDB_ERROR ecode;
 
 	/* Front of list? */
 	if (frec_prev(r) == 0) {
@@ -116,105 +118,116 @@ static int remove_from_list(struct tdb_context *tdb,
 		off = frec_prev(r) + offsetof(struct tdb_free_record, next);
 	}
 
-#ifdef DEBUG
+#ifdef CCAN_TDB2_DEBUG
 	if (tdb_read_off(tdb, off) != r_off) {
-		tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
-			 "remove_from_list: %llu bad prev in list %llu\n",
-			 (long long)r_off, (long long)b_off);
-		return -1;
+		return tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
+				  "remove_from_list:"
+				  " %llu bad prev in list %llu",
+				  (long long)r_off, (long long)b_off);
 	}
 #endif
 
 	/* r->prev->next = r->next */
-	if (tdb_write_off(tdb, off, r->next)) {
-		return -1;
+	ecode = tdb_write_off(tdb, off, r->next);
+	if (ecode != TDB_SUCCESS) {
+		return ecode;
 	}
 
 	if (r->next != 0) {
 		off = r->next + offsetof(struct tdb_free_record,magic_and_prev);
 		/* r->next->prev = r->prev */
 
-#ifdef DEBUG
+#ifdef CCAN_TDB2_DEBUG
 		if (tdb_read_off(tdb, off) & TDB_OFF_MASK != r_off) {
-			tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
-				 "remove_from_list: %llu bad list %llu\n",
-				 (long long)r_off, (long long)b_off);
-			return -1;
+			return tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
+					  "remove_from_list:"
+					  " %llu bad list %llu",
+					  (long long)r_off, (long long)b_off);
 		}
 #endif
 
-		if (tdb_write_off(tdb, off, r->magic_and_prev)) {
-			return -1;
+		ecode = tdb_write_off(tdb, off, r->magic_and_prev);
+		if (ecode != TDB_SUCCESS) {
+			return ecode;
 		}
 	}
-	return 0;
+	return TDB_SUCCESS;
 }
 
 /* Enqueue in this free bucket. */
-static int enqueue_in_free(struct tdb_context *tdb,
-			   tdb_off_t b_off,
-			   tdb_off_t off,
-			   tdb_len_t len)
+static enum TDB_ERROR enqueue_in_free(struct tdb_context *tdb,
+				      tdb_off_t b_off,
+				      tdb_off_t off,
+				      tdb_len_t len)
 {
 	struct tdb_free_record new;
+	enum TDB_ERROR ecode;
 	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;
 
 	/* new->next = head. */
 	new.next = tdb_read_off(tdb, b_off);
-	if (new.next == TDB_OFF_ERR)
-		return -1;
+	if (TDB_OFF_IS_ERR(new.next)) {
+		return new.next;
+	}
 
 	if (new.next) {
-#ifdef DEBUG
+#ifdef CCAN_TDB2_DEBUG
 		if (tdb_read_off(tdb,
 				 new.next + offsetof(struct tdb_free_record,
 						     magic_and_prev))
 		    != magic) {
-			tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
-				 "enqueue_in_free: %llu bad head prev %llu\n",
-				 (long long)new.next, (long long)b_off);
-			return -1;
+			return tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
+					  "enqueue_in_free: %llu bad head"
+					  " prev %llu",
+					  (long long)new.next,
+					  (long long)b_off);
 		}
 #endif
 		/* next->prev = new. */
-		if (tdb_write_off(tdb, new.next
-				  + offsetof(struct tdb_free_record,
-					     magic_and_prev),
-				  off | magic) != 0)
-			return -1;
+		ecode = tdb_write_off(tdb, new.next
+				      + offsetof(struct tdb_free_record,
+						 magic_and_prev),
+				      off | magic);
+		if (ecode != TDB_SUCCESS) {
+			return ecode;
+		}
 	}
 	/* head = new */
-	if (tdb_write_off(tdb, b_off, off) != 0)
-		return -1;
+	ecode = tdb_write_off(tdb, b_off, off);
+	if (ecode != TDB_SUCCESS) {
+		return ecode;
+	}
 
 	return tdb_write_convert(tdb, off, &new, sizeof(new));
 }
 
 /* List need not be locked. */
-int add_free_record(struct tdb_context *tdb,
-		    tdb_off_t off, tdb_len_t len_with_header)
+enum TDB_ERROR add_free_record(struct tdb_context *tdb,
+			       tdb_off_t off, tdb_len_t len_with_header)
 {
 	tdb_off_t b_off;
 	tdb_len_t len;
-	int ret;
+	enum TDB_ERROR ecode;
 
 	assert(len_with_header >= sizeof(struct tdb_free_record));
 
 	len = len_with_header - sizeof(struct tdb_used_record);
 
-	b_off = bucket_off(tdb->flist_off, size_to_bucket(len));
-	if (tdb_lock_free_bucket(tdb, b_off, TDB_LOCK_WAIT) != 0)
-		return -1;
+	b_off = bucket_off(tdb->ftable_off, size_to_bucket(len));
+	ecode = tdb_lock_free_bucket(tdb, b_off, TDB_LOCK_WAIT);
+	if (ecode != TDB_SUCCESS) {
+		return ecode;
+	}
 
-	ret = enqueue_in_free(tdb, b_off, off, len);
+	ecode = enqueue_in_free(tdb, b_off, off, len);
 	tdb_unlock_free_bucket(tdb, b_off);
-	return ret;
+	return ecode;
 }
 
 static size_t adjust_size(size_t keylen, size_t datalen)
@@ -244,148 +257,177 @@ static size_t record_leftover(size_t keylen, size_t datalen,
 	return leftover;
 }
 
-/* FIXME: Shortcut common case where tdb->flist == flist */
-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 = first_flist(tdb);
+	tdb_off_t off;
 	unsigned int i;
 
-	for (i = 0; i < flist; i++)
-		off = next_flist(tdb, off);
+	if (likely(tdb->ftable == ftable))
+		return tdb->ftable_off;
+
+	off = first_ftable(tdb);
+	for (i = 0; i < ftable; i++) {
+		if (TDB_OFF_IS_ERR(off)) {
+			break;
+		}
+		off = next_ftable(tdb, off);
+	}
 	return off;
 }
 
 /* Note: we unlock the current bucket if we coalesce or fail. */
-static int coalesce(struct tdb_context *tdb,
-		    tdb_off_t off, tdb_off_t b_off, tdb_len_t data_len)
+static tdb_bool_err coalesce(struct tdb_context *tdb,
+			     tdb_off_t off, tdb_off_t b_off,
+			     tdb_len_t data_len)
 {
-	struct tdb_free_record pad, *r;
 	tdb_off_t end;
+	struct tdb_free_record rec;
+	enum TDB_ERROR ecode;
 
 	add_stat(tdb, alloc_coalesce_tried, 1);
 	end = off + sizeof(struct tdb_used_record) + data_len;
 
-	while (end < tdb->map_size) {
+	while (end < tdb->file->map_size) {
+		const struct tdb_free_record *r;
 		tdb_off_t nb_off;
-		unsigned flist, bucket;
+		unsigned ftable, bucket;
 
-		/* FIXME: do tdb_get here and below really win? */
-		r = tdb_get(tdb, end, &pad, sizeof(pad));
-		if (!r)
+		r = tdb_access_read(tdb, end, sizeof(*r), true);
+		if (TDB_PTR_IS_ERR(r)) {
+			ecode = TDB_PTR_ERR(r);
 			goto err;
+		}
 
-		if (frec_magic(r) != TDB_FREE_MAGIC)
+		if (frec_magic(r) != TDB_FREE_MAGIC
+		    || 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 = ftable_offset(tdb, ftable);
+		if (TDB_OFF_IS_ERR(nb_off)) {
+			tdb_access_release(tdb, r);
+			ecode = nb_off;
+			goto err;
+		}
+		nb_off = bucket_off(nb_off, bucket);
+		tdb_access_release(tdb, r);
 
 		/* We may be violating lock order here, so best effort. */
-		if (tdb_lock_free_bucket(tdb, nb_off, TDB_LOCK_NOWAIT) == -1) {
+		if (tdb_lock_free_bucket(tdb, nb_off, TDB_LOCK_NOWAIT)
+		    != TDB_SUCCESS) {
 			add_stat(tdb, alloc_coalesce_lockfail, 1);
 			break;
 		}
 
 		/* Now we have lock, re-check. */
-		r = tdb_get(tdb, end, &pad, sizeof(pad));
-		if (!r) {
+		ecode = tdb_read_convert(tdb, end, &rec, sizeof(rec));
+		if (ecode != TDB_SUCCESS) {
 			tdb_unlock_free_bucket(tdb, nb_off);
 			goto err;
 		}
 
-		if (unlikely(frec_magic(r) != TDB_FREE_MAGIC)) {
+		if (unlikely(frec_magic(&rec) != TDB_FREE_MAGIC)) {
 			add_stat(tdb, alloc_coalesce_race, 1);
 			tdb_unlock_free_bucket(tdb, nb_off);
 			break;
 		}
 
-		if (unlikely(frec_flist(r) != flist)
-		    || unlikely(size_to_bucket(frec_len(r)) != bucket)) {
+		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);
 			break;
 		}
 
-		if (remove_from_list(tdb, nb_off, end, r) == -1) {
+		ecode = remove_from_list(tdb, nb_off, end, &rec);
+		if (ecode != TDB_SUCCESS) {
 			tdb_unlock_free_bucket(tdb, nb_off);
 			goto err;
 		}
 
-		end += sizeof(struct tdb_used_record) + frec_len(r);
+		end += sizeof(struct tdb_used_record) + frec_len(&rec);
 		tdb_unlock_free_bucket(tdb, nb_off);
 		add_stat(tdb, alloc_coalesce_num_merged, 1);
 	}
 
 	/* Didn't find any adjacent free? */
 	if (end == off + sizeof(struct tdb_used_record) + data_len)
-		return 0;
+		return false;
 
-	/* OK, expand record */
-	r = tdb_get(tdb, off, &pad, sizeof(pad));
-	if (!r)
-		goto err;
-
-	if (frec_len(r) != data_len) {
-		tdb->ecode = TDB_ERR_CORRUPT;
-		tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
-			 "coalesce: expected data len %llu not %llu\n",
-			 (long long)data_len, (long long)frec_len(r));
+	/* OK, expand initial record */
+	ecode = tdb_read_convert(tdb, off, &rec, sizeof(rec));
+	if (ecode != TDB_SUCCESS) {
 		goto err;
 	}
 
-	if (remove_from_list(tdb, b_off, off, r) == -1)
+	if (frec_len(&rec) != data_len) {
+		ecode = tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
+				   "coalesce: expected data len %zu not %zu",
+				   (size_t)data_len, (size_t)frec_len(&rec));
 		goto err;
+	}
 
-	r = tdb_access_write(tdb, off, sizeof(*r), true);
-	if (!r)
+	ecode = remove_from_list(tdb, b_off, off, &rec);
+	if (ecode != TDB_SUCCESS) {
 		goto err;
+	}
 
 	/* We have to drop this to avoid deadlocks, so make sure record
 	 * doesn't get coalesced by someone else! */
-	r->magic_and_prev = TDB_COALESCING_MAGIC << (64 - TDB_OFF_UPPER_STEAL);
-	/* FIXME: Use 255 as invalid free list? */
-	r->flist_and_len = end - off - sizeof(struct tdb_used_record);
-	if (tdb_access_commit(tdb, r) != 0)
+	rec.ftable_and_len = (TDB_FTABLE_NONE << (64 - TDB_OFF_UPPER_STEAL))
+		| (end - off - sizeof(struct tdb_used_record));
+	ecode = tdb_write_off(tdb, off + offsetof(struct tdb_free_record,
+						  ftable_and_len),
+			      rec.ftable_and_len);
+	if (ecode != TDB_SUCCESS) {
 		goto err;
+	}
 
 	add_stat(tdb, alloc_coalesce_succeeded, 1);
 	tdb_unlock_free_bucket(tdb, b_off);
 
-	if (add_free_record(tdb, off, end - off) == -1)
-		return -1;
-	return 1;
+	ecode = add_free_record(tdb, off, end - off);
+	if (ecode != TDB_SUCCESS) {
+		return ecode;
+	}
+	return true;
 
 err:
 	/* To unify error paths, we *always* unlock bucket on error. */
 	tdb_unlock_free_bucket(tdb, b_off);
-	return -1;
+	return ecode;
 }
 
 /* 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;
-	struct tdb_free_record pad, best = { 0 }, *r;
+	struct tdb_free_record best = { 0 };
 	double multiplier;
 	size_t size = adjust_size(keylen, datalen);
+	enum TDB_ERROR ecode;
 
 	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. */
-	if (tdb_lock_free_bucket(tdb, b_off, TDB_LOCK_WAIT) == -1) {
-		return TDB_OFF_ERR;
+	ecode = tdb_lock_free_bucket(tdb, b_off, TDB_LOCK_WAIT);
+	if (ecode != TDB_SUCCESS) {
+		return ecode;
 	}
 
-	best.flist_and_len = -1ULL;
+	best.ftable_and_len = -1ULL;
 	best_off = 0;
 
 	/* Get slack if we're after extra. */
@@ -397,19 +439,30 @@ again:
 	/* Walk the list to see if any are large enough, getting less fussy
 	 * as we go. */
 	off = tdb_read_off(tdb, b_off);
-	if (unlikely(off == TDB_OFF_ERR))
+	if (TDB_OFF_IS_ERR(off)) {
+		ecode = off;
 		goto unlock_err;
+	}
 
 	while (off) {
-		/* FIXME: Does tdb_get win anything here? */
-		r = tdb_get(tdb, off, &pad, sizeof(*r));
-		if (!r)
+		const struct tdb_free_record *r;
+		tdb_len_t len;
+		tdb_off_t next;
+		int coal;
+
+		r = tdb_access_read(tdb, off, sizeof(*r), true);
+		if (TDB_PTR_IS_ERR(r)) {
+			ecode = TDB_PTR_ERR(r);
 			goto unlock_err;
+		}
 
 		if (frec_magic(r) != TDB_FREE_MAGIC) {
-			tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-				 "lock_and_alloc: %llu non-free 0x%llx\n",
-				 (long long)off, (long long)r->magic_and_prev);
+			ecode = tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
+					   "lock_and_alloc:"
+					   " %llu non-free 0x%llx",
+					   (long long)off,
+					   (long long)r->magic_and_prev);
+			tdb_access_release(tdb, r);
 			goto unlock_err;
 		}
 
@@ -418,21 +471,28 @@ again:
 			best = *r;
 		}
 
-		if (frec_len(&best) < size * multiplier && best_off)
+		if (frec_len(&best) < size * multiplier && best_off) {
+			tdb_access_release(tdb, r);
 			break;
+		}
 
 		multiplier *= 1.01;
 
+		next = r->next;
+		len = frec_len(r);
+		tdb_access_release(tdb, r);
+
 		/* Since we're going slow anyway, try coalescing here. */
-		switch (coalesce(tdb, off, b_off, frec_len(r))) {
-		case -1:
-			/* This has already unlocked on error. */
-			return -1;
-		case 1:
+		coal = coalesce(tdb, off, b_off, len);
+		if (coal == 1) {
 			/* This has unlocked list, restart. */
 			goto again;
 		}
-		off = r->next;
+		if (coal < 0) {
+			/* This has already unlocked on error. */
+			return coal;
+		}
+		off = next;
 	}
 
 	/* If we found anything at all, use it. */
@@ -441,8 +501,10 @@ again:
 		size_t leftover;
 
 		/* We're happy with this size: take it. */
-		if (remove_from_list(tdb, b_off, best_off, &best) != 0)
+		ecode = remove_from_list(tdb, b_off, best_off, &best);
+		if (ecode != TDB_SUCCESS) {
 			goto unlock_err;
+		}
 
 		leftover = record_leftover(keylen, datalen, want_extra,
 					   frec_len(&best));
@@ -450,23 +512,37 @@ 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)
+		ecode = set_header(tdb, &rec, magic, keylen, datalen,
+				   frec_len(&best) - leftover, hashlow);
+		if (ecode != TDB_SUCCESS) {
 			goto unlock_err;
+		}
 
-		if (tdb_write_convert(tdb, best_off, &rec, sizeof(rec)) != 0)
+		ecode = tdb_write_convert(tdb, best_off, &rec, sizeof(rec));
+		if (ecode != TDB_SUCCESS) {
 			goto unlock_err;
+		}
+
+		/* For futureproofing, we put a 0 in any unused space. */
+		if (rec_extra_padding(&rec)) {
+			ecode = tdb->methods->twrite(tdb, best_off + sizeof(rec)
+						     + keylen + datalen, "", 1);
+			if (ecode != TDB_SUCCESS) {
+				goto unlock_err;
+			}
+		}
 
 		/* Bucket of leftover will be <= current bucket, so nested
 		 * locking is allowed. */
 		if (leftover) {
 			add_stat(tdb, alloc_leftover, 1);
-			if (add_free_record(tdb,
-					    best_off + sizeof(rec)
-					    + frec_len(&best) - leftover,
-					    leftover))
-				best_off = TDB_OFF_ERR;
+			ecode = add_free_record(tdb,
+						best_off + sizeof(rec)
+						+ frec_len(&best) - leftover,
+						leftover);
+			if (ecode != TDB_SUCCESS) {
+				best_off = ecode;
+			}
 		}
 		tdb_unlock_free_bucket(tdb, b_off);
 
@@ -478,16 +554,16 @@ again:
 
 unlock_err:
 	tdb_unlock_free_bucket(tdb, b_off);
-	return TDB_OFF_ERR;
+	return ecode;
 }
 
-/* Get a free block from current free list, or 0 if none. */
+/* Get a free block from current free list, or 0 if none, -ve on error. */
 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;
+	tdb_off_t start_b, b, ftable;
 	bool wrapped = false;
 
 	/* If they are growing, add 50% to get to higher bucket. */
@@ -497,50 +573,60 @@ 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);
-			if (off == TDB_OFF_ERR)
-				return TDB_OFF_ERR;
+					     magic, hashlow);
+			if (TDB_OFF_IS_ERR(off))
+				return off;
 			if (off != 0) {
 				if (b == start_b)
 					add_stat(tdb, alloc_bucket_exact, 1);
 				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++;
+		if (TDB_OFF_IS_ERR(b)) {
+			return b;
+		}
+
+		/* Hmm, try next table. */
+		ftable_off = next_ftable(tdb, ftable_off);
+		if (TDB_OFF_IS_ERR(ftable_off)) {
+			return 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);
+			if (TDB_OFF_IS_ERR(ftable_off)) {
+				return ftable_off;
+			}
+			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)
+enum TDB_ERROR 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;
 
@@ -548,63 +634,64 @@ 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. */
 	if (rec_key_length(rec) != keylen
 	    || rec_data_length(rec) != datalen
 	    || rec_extra_padding(rec) != actuallen - (keylen + datalen)) {
-		tdb->ecode = TDB_ERR_IO;
-		tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-			 "Could not encode k=%llu,d=%llu,a=%llu\n",
-			 (long long)keylen, (long long)datalen,
-			 (long long)actuallen);
-		return -1;
+		return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+				  "Could not encode k=%llu,d=%llu,a=%llu",
+				  (long long)keylen, (long long)datalen,
+				  (long long)actuallen);
 	}
-	return 0;
+	return TDB_SUCCESS;
 }
 
 /* Expand the database. */
-static int tdb_expand(struct tdb_context *tdb, tdb_len_t size)
+static enum TDB_ERROR tdb_expand(struct tdb_context *tdb, tdb_len_t size)
 {
 	uint64_t old_size;
 	tdb_len_t wanted;
+	enum TDB_ERROR ecode;
 
 	/* 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;
+	    && !tdb->file->allrecord_lock.count && !tdb_has_hash_locks(tdb)) {
+		return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR,
+				  "tdb_expand: must hold lock during expand");
 	}
 
 	/* always make room for at least 100 more records, and at
            least 25% more space. */
-	if (size * TDB_EXTENSION_FACTOR > tdb->map_size / 4)
+	if (size * TDB_EXTENSION_FACTOR > tdb->file->map_size / 4)
 		wanted = size * TDB_EXTENSION_FACTOR;
 	else
-		wanted = tdb->map_size / 4;
+		wanted = tdb->file->map_size / 4;
 	wanted = adjust_size(0, wanted);
 
 	/* Only one person can expand file at a time. */
-	if (tdb_lock_expand(tdb, F_WRLCK) != 0)
-		return -1;
+	ecode = tdb_lock_expand(tdb, F_WRLCK);
+	if (ecode != TDB_SUCCESS) {
+		return ecode;
+	}
 
 	/* 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) {
+	old_size = tdb->file->map_size;
+	tdb->methods->oob(tdb, tdb->file->map_size + 1, true);
+	if (tdb->file->map_size != old_size) {
 		tdb_unlock_expand(tdb, F_WRLCK);
-		return 0;
+		return TDB_SUCCESS;
 	}
 
-	if (tdb->methods->expand_file(tdb, wanted) == -1) {
+	ecode = tdb->methods->expand_file(tdb, wanted);
+	if (ecode != TDB_SUCCESS) {
 		tdb_unlock_expand(tdb, F_WRLCK);
-		return -1;
+		return ecode;
 	}
 
 	/* We need to drop this lock before adding free record. */
@@ -616,7 +703,7 @@ 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;
 
@@ -624,12 +711,15 @@ 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);
+		enum TDB_ERROR ecode;
+		off = get_free(tdb, keylen, datalen, growing, magic, hash);
 		if (likely(off != 0))
 			break;
 
-		if (tdb_expand(tdb, adjust_size(keylen, datalen)))
-			return TDB_OFF_ERR;
+		ecode = tdb_expand(tdb, adjust_size(keylen, datalen));
+		if (ecode != TDB_SUCCESS) {
+			return ecode;
+		}
 	}
 
 	return off;