3 files changed, 34 insertions, 21 deletions

diff --git a/lib/tdb/common/io.c b/lib/tdb/common/io.c
index a2db3bf4bd8..ac21e3f67a1 100644
--- a/lib/tdb/common/io.c
+++ b/lib/tdb/common/io.c
@@ -313,41 +313,49 @@ static int tdb_expand_file(struct tdb_context *tdb, tdb_off_t size, tdb_off_t ad
 }
 
 
-/* expand the database at least size bytes by expanding the underlying
-   file and doing the mmap again if necessary */
-int tdb_expand(struct tdb_context *tdb, tdb_off_t size)
+/* You need 'size', this tells you how much you should expand by. */
+tdb_off_t tdb_expand_adjust(tdb_off_t map_size, tdb_off_t size, int page_size)
 {
-	struct tdb_record rec;
-	tdb_off_t offset, new_size, top_size, map_size;
-
-	if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_ERROR, "lock failed in tdb_expand\n"));
-		return -1;
-	}
-
-	/* must know about any previous expansions by another process */
-	tdb->methods->tdb_oob(tdb, tdb->map_size, 1, 1);
+	tdb_off_t new_size, top_size;
 
 	/* limit size in order to avoid using up huge amounts of memory for
 	 * in memory tdbs if an oddball huge record creeps in */
 	if (size > 100 * 1024) {
-		top_size = tdb->map_size + size * 2;
+		top_size = map_size + size * 2;
 	} else {
-		top_size = tdb->map_size + size * 100;
+		top_size = map_size + size * 100;
 	}
 
 	/* always make room for at least top_size more records, and at
 	   least 25% more space. if the DB is smaller than 100MiB,
 	   otherwise grow it by 10% only. */
-	if (tdb->map_size > 100 * 1024 * 1024) {
-		map_size = tdb->map_size * 1.10;
+	if (map_size > 100 * 1024 * 1024) {
+		new_size = map_size * 1.10;
 	} else {
-		map_size = tdb->map_size * 1.25;
+		new_size = map_size * 1.25;
 	}
 
 	/* Round the database up to a multiple of the page size */
-	new_size = MAX(top_size, map_size);
-	size = TDB_ALIGN(new_size, tdb->page_size) - tdb->map_size;
+	new_size = MAX(top_size, new_size);
+	return TDB_ALIGN(new_size, page_size) - map_size;
+}
+
+/* expand the database at least size bytes by expanding the underlying
+   file and doing the mmap again if necessary */
+int tdb_expand(struct tdb_context *tdb, tdb_off_t size)
+{
+	struct tdb_record rec;
+	tdb_off_t offset;
+
+	if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
+		TDB_LOG((tdb, TDB_DEBUG_ERROR, "lock failed in tdb_expand\n"));
+		return -1;
+	}
+
+	/* must know about any previous expansions by another process */
+	tdb->methods->tdb_oob(tdb, tdb->map_size, 1, 1);
+
+	size = tdb_expand_adjust(tdb->map_size, size, tdb->page_size);
 
 	if (!(tdb->flags & TDB_INTERNAL))
 		tdb_munmap(tdb);
diff --git a/lib/tdb/common/tdb_private.h b/lib/tdb/common/tdb_private.h
index 3c6aabffc76..4fc7381aa04 100644
--- a/lib/tdb/common/tdb_private.h
+++ b/lib/tdb/common/tdb_private.h
@@ -271,6 +271,7 @@ tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t has
 			   struct tdb_record *rec);
 void tdb_io_init(struct tdb_context *tdb);
 int tdb_expand(struct tdb_context *tdb, tdb_off_t size);
+tdb_off_t tdb_expand_adjust(tdb_off_t map_size, tdb_off_t size, int page_size);
 int tdb_rec_free_read(struct tdb_context *tdb, tdb_off_t off,
 		      struct tdb_record *rec);
 bool tdb_write_all(int fd, const void *buf, size_t count);
diff --git a/lib/tdb/common/transaction.c b/lib/tdb/common/transaction.c
index 66ecbfdefb6..f7d56a05a36 100644
--- a/lib/tdb/common/transaction.c
+++ b/lib/tdb/common/transaction.c
@@ -730,7 +730,11 @@ static int tdb_recovery_allocate(struct tdb_context *tdb,
 	*recovery_size = tdb_recovery_size(tdb);
 
 	/* round up to a multiple of page size */
-	*recovery_max_size = TDB_ALIGN(sizeof(rec) + *recovery_size, tdb->page_size) - sizeof(rec);
+	*recovery_max_size = tdb_expand_adjust(tdb->map_size,
+					       *recovery_size,
+					       tdb->page_size)
+		- sizeof(rec);
+
 	*recovery_offset = tdb->map_size;
 	recovery_head = *recovery_offset;