xenstore: call add_change_node() directly when writing node

Instead of calling add_change_node() at places where write_node() is
called, do that inside write_node().

Note that there is one case where add_change_node() is called now when
a later failure will prohibit the changed node to be written: in case
of a write_node failing due to an error in tdb_store(). As the only
visible change of behavior is a stale event fired for the node, while
the failing tdb_store() signals a corrupted xenstore database, the
stale event will be the least problem of this case.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>

diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index de1a9b4e8ac60b5bf06ea86dffe62fc11cd98557..1354387fc19e61832c730420534950b1819e0607 100644 (file)
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -456,7 +456,7 @@ static struct node *read_node(struct connection *conn, const void *ctx,
        return node;
 }
 
-static bool write_node(struct connection *conn, const struct node *node)
+static bool write_node(struct connection *conn, struct node *node)
 {
        /*
         * conn will be null when this is called from manual_node.
@@ -476,6 +476,8 @@ static bool write_node(struct connection *conn, const struct node *node)
        if (domain_is_unprivileged(conn) && data.dsize >= quota_max_entry_size)
                goto error;
 
+       add_change_node(conn, node, false);
+
        data.dptr = talloc_size(node, data.dsize);
        ((uint32_t *)data.dptr)[0] = node->num_perms;
        ((uint32_t *)data.dptr)[1] = node->datalen;
@@ -976,7 +978,6 @@ static void do_write(struct connection *conn, struct buffered_data *in)
                }
        }
 
-       add_change_node(conn, node, false);
        fire_watches(conn, in, name, false);
        send_ack(conn, XS_WRITE);
 }
@@ -1007,7 +1008,6 @@ static void do_mkdir(struct connection *conn, struct buffered_data *in)
                        send_error(conn, errno);
                        return;
                }
-               add_change_node(conn, node, false);
                fire_watches(conn, in, name, false);
        }
        send_ack(conn, XS_MKDIR);
@@ -1209,7 +1209,6 @@ static void do_set_perms(struct connection *conn, struct buffered_data *in)
                return;
        }
 
-       add_change_node(conn, node, false);
        fire_watches(conn, in, name, false);
        send_ack(conn, XS_SET_PERMS);
 }