tdb2: stricter ordering on expansion lock

[ccan] / ccan / tdb2 / free.c

diff --git a/ccan/tdb2/free.c b/ccan/tdb2/free.c
index ac637ce1c8650caab593036c143bce5b1b65bc47..8f81f9d99aae0a378db0163e6cd389bda336d060 100644 (file)
--- a/ccan/tdb2/free.c
+++ b/ccan/tdb2/free.c
@@ -530,6 +530,14 @@ static int tdb_expand(struct tdb_context *tdb, tdb_len_t size)
        /* 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;