Re: [libvirt] [PATCH v3 2/6] virConnectRegisterCloseCallback: Cleanup 'opaque' if there is no connectRegisterCloseCallback

The commit 'close callback: move it to driver' (88f09b75eb99) moved the responsibility for the close callback to the driver. But if the driver doesn't support the connectRegisterCloseCallback API this function does nothing, even no unsupported error report. This behavior may lead to problems, for example memory leaks, as the caller cannot differentiate whether the close callback was 'really' registered or not. Therefore call directly @freecb if the connectRegisterCloseCallback API is not supported by the driver used by the connection. Signed-off-by: Marc Hartmayer <mhartmay(a)linux.ibm.com&gt; --- src/libvirt-host.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/src/libvirt-host.c b/src/libvirt-host.c index 221a1b7a4353..9c3a19f33b12 100644 --- a/src/libvirt-host.c +++ b/src/libvirt-host.c @@ -1398,7 +1398,7 @@ virConnectIsAlive(virConnectPtr conn) * @conn: pointer to connection object * @cb: callback to invoke upon close * @opaque: user data to pass to @cb - * @freecb: callback to free @opaque + * @freecb: callback to free @opaque when not used anymore * * Registers a callback to be invoked when the connection * is closed. This callback is invoked when there is any @@ -1428,9 +1428,13 @@ virConnectRegisterCloseCallback(virConnectPtr conn, virCheckConnectReturn(conn, -1); virCheckNonNullArgGoto(cb, error); - if (conn->driver->connectRegisterCloseCallback && - conn->driver->connectRegisterCloseCallback(conn, cb, opaque, freecb) < 0) - goto error; + if (conn->driver->connectRegisterCloseCallback) { + if (conn->driver->connectRegisterCloseCallback(conn, cb, opaque, freecb) < 0) + goto error; + } else { + if (freecb) + freecb(opaque); + }