"Daniel P. Berrange" <berrange@redhat.com> wrote:
We are using DBus from multiple threads in libvirtd. We are not calling dbus_threads_init_default(). Very bad things result. Happy-crashy-daemon
This patch fixes that, and also stops DBus messing around with SIGPIPE and also stops it calling exit() when the bus disconnects, so we can actually see the error & continue with life.
These all look fine. I can attest to having stared hard at dbus' SIGPIPE-handling code (and asking why, oh why, a *library* handles a signal, by default) so am glad to see it turned off here. However, now there are 3 dbus-init-related lines in each of those files, not counting the slightly-separated *_set_exit_on_disconnect call. It'd be nice to encapsulate those, or at least to add a comment before each saying to keep them in sync. Hmm. actually there are four calls in each place: dbus_connection_set_change_sigpipe(FALSE); dbus_threads_init_default(); dbus_error_init ... = dbus_bus_get(... Only the last one can fail. For the record, are these crashes easy to reproduce?
diff -rup libvirt-0.6.0.orig/qemud/qemud.c libvirt-0.6.0.new/qemud/qemud.c --- libvirt-0.6.0.orig/qemud/qemud.c 2009-02-18 10:56:34.000000000 +0000 +++ libvirt-0.6.0.new/qemud/qemud.c 2009-02-18 12:52:18.000000000 +0000 @@ -860,6 +860,10 @@ static struct qemud_server *qemudNetwork if (auth_unix_rw == REMOTE_AUTH_POLKIT || auth_unix_ro == REMOTE_AUTH_POLKIT) { DBusError derr; + + dbus_connection_set_change_sigpipe(FALSE); + dbus_threads_init_default(); + dbus_error_init(&derr); server->sysbus = dbus_bus_get(DBUS_BUS_SYSTEM, &derr); if (!(server->sysbus)) { @@ -868,6 +872,7 @@ static struct qemud_server *qemudNetwork dbus_error_free(&derr); goto cleanup; } + dbus_connection_set_exit_on_disconnect(server->sysbus, FALSE); } #endif
diff -rup libvirt-0.6.0.orig/src/node_device_hal.c libvirt-0.6.0.new/src/node_device_hal.c --- libvirt-0.6.0.orig/src/node_device_hal.c 2009-01-16 12:44:22.000000000 +0000 +++ libvirt-0.6.0.new/src/node_device_hal.c 2009-02-18 12:52:48.000000000 +0000 @@ -685,6 +685,9 @@ static int halDeviceMonitorStartup(void) nodeDeviceLock(driverState);
/* Allocate and initialize a new HAL context */ + dbus_connection_set_change_sigpipe(FALSE); + dbus_threads_init_default(); + dbus_error_init(&err); hal_ctx = libhal_ctx_new(); if (hal_ctx == NULL) { @@ -696,6 +699,8 @@ static int halDeviceMonitorStartup(void) fprintf(stderr, "%s: dbus_bus_get failed\n", __FUNCTION__); goto failure; } + dbus_connection_set_exit_on_disconnect(dbus_conn, FALSE); + if (!libhal_ctx_set_dbus_connection(hal_ctx, dbus_conn)) { fprintf(stderr, "%s: libhal_ctx_set_dbus_connection failed\n", __FUNCTION__);