X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Ftdb.c;h=42e75f9d1840b8f79875f01ac05b6637a6d9f358;hp=ce431208bf4cb4fa28d09f9158c7fb02c93d7d37;hb=ed81f39468c4d9089310fb4950b09c1f5886c4ef;hpb=95c98eb3ee9fcb3913ecb6c2618fcdaf3c8ce60a

diff --git a/ccan/tdb2/tdb.c b/ccan/tdb2/tdb.c
index ce431208..42e75f9d 100644
--- a/ccan/tdb2/tdb.c
+++ b/ccan/tdb2/tdb.c
@@ -112,6 +112,7 @@ static enum TDB_ERROR tdb_new_database(struct tdb_context *tdb,
 					 newdb.hdr.hash_seed,
 					 tdb->hash_priv);
 	newdb.hdr.recovery = 0;
+	newdb.hdr.features_used = newdb.hdr.features_offered = TDB_FEATURE_MASK;
 	memset(newdb.hdr.reserved, 0, sizeof(newdb.hdr.reserved));
 	/* Initial hashes are empty. */
 	memset(newdb.hdr.hashtable, 0, sizeof(newdb.hdr.hashtable));
@@ -361,6 +362,16 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 		goto fail;
 	}
 
+	/* Clear any features we don't understand. */
+ 	if ((open_flags & O_ACCMODE) != O_RDONLY) {
+		hdr.features_used &= TDB_FEATURE_MASK;
+		if (tdb_write_convert(tdb, offsetof(struct tdb_header,
+						    features_used),
+				      &hdr.features_used,
+				      sizeof(hdr.features_used)) == -1)
+			goto fail;
+	}
+
 	tdb->device = st.st_dev;
 	tdb->inode = st.st_ino;
 	tdb_unlock_open(tdb);
@@ -499,6 +510,21 @@ static enum TDB_ERROR replace_data(struct tdb_context *tdb,
 	return TDB_SUCCESS;
 }
 
+static enum TDB_ERROR update_data(struct tdb_context *tdb,
+				  tdb_off_t off,
+				  struct tdb_data dbuf,
+				  tdb_len_t extra)
+{
+	enum TDB_ERROR ecode;
+
+	ecode = tdb->methods->twrite(tdb, off, dbuf.dptr, dbuf.dsize);
+	if (ecode == TDB_SUCCESS && extra) {
+		/* Put a zero in; future versions may append other data. */
+		ecode = tdb->methods->twrite(tdb, off + dbuf.dsize, "", 1);
+	}
+	return ecode;
+}
+
 enum TDB_ERROR tdb_store(struct tdb_context *tdb,
 			 struct tdb_data key, struct tdb_data dbuf, int flag)
 {
@@ -531,11 +557,10 @@ enum TDB_ERROR tdb_store(struct tdb_context *tdb,
 				if (ecode != TDB_SUCCESS) {
 					goto out;
 				}
-				ecode = tdb->methods->twrite(tdb,
-							     off + sizeof(rec)
-							     + key.dsize,
-							     dbuf.dptr,
-							     dbuf.dsize);
+				ecode = update_data(tdb,
+						    off + sizeof(rec)
+						    + key.dsize, dbuf,
+						    old_room - dbuf.dsize);
 				if (ecode != TDB_SUCCESS) {
 					goto out;
 				}
@@ -591,8 +616,8 @@ enum TDB_ERROR tdb_append(struct tdb_context *tdb,
 			}
 
 			off += sizeof(rec) + key.dsize + old_dlen;
-			ecode = tdb->methods->twrite(tdb, off, dbuf.dptr,
-						     dbuf.dsize);
+			ecode = update_data(tdb, off, dbuf,
+					    rec_extra_padding(&rec));
 			goto out;
 		}