net/colo-compare.c: Check that colo-compare is active

If the colo-compare object is removed before failover and a
checkpoint happens, qemu crashes because it tries to lock
the destroyed event_mtx in colo_notify_compares_event.

Fix this by checking if everything is initialized by
introducing a new variable colo_compare_active which
is protected by a new mutex colo_compare_mutex. The new mutex
also protects against concurrent access of the net_compares
list and makes sure that colo_notify_compares_event isn't
active while we destroy event_mtx and event_complete_cond.

With this it also is again possible to use colo without
colo-compare (periodic mode) and to use multiple colo-compare
for multiple network interfaces.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Tested-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Zhang Chen <chen.zhang@intel.com>
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Lukas Straub 2020-05-22 15:53:55 +08:00 committed by Jason Wang
parent 76658541f3
commit 45942b79b9

View File

@ -54,6 +54,8 @@ static NotifierList colo_compare_notifiers =
#define REGULAR_PACKET_CHECK_MS 3000
#define DEFAULT_TIME_OUT_MS 3000
static QemuMutex colo_compare_mutex;
static bool colo_compare_active;
static QemuMutex event_mtx;
static QemuCond event_complete_cond;
static int event_unhandled_count;
@ -906,6 +908,12 @@ static void check_old_packet_regular(void *opaque)
void colo_notify_compares_event(void *opaque, int event, Error **errp)
{
CompareState *s;
qemu_mutex_lock(&colo_compare_mutex);
if (!colo_compare_active) {
qemu_mutex_unlock(&colo_compare_mutex);
return;
}
qemu_mutex_lock(&event_mtx);
QTAILQ_FOREACH(s, &net_compares, next) {
@ -919,6 +927,7 @@ void colo_notify_compares_event(void *opaque, int event, Error **errp)
}
qemu_mutex_unlock(&event_mtx);
qemu_mutex_unlock(&colo_compare_mutex);
}
static void colo_compare_timer_init(CompareState *s)
@ -1274,7 +1283,14 @@ static void colo_compare_complete(UserCreatable *uc, Error **errp)
s->vnet_hdr);
}
qemu_mutex_lock(&colo_compare_mutex);
if (!colo_compare_active) {
qemu_mutex_init(&event_mtx);
qemu_cond_init(&event_complete_cond);
colo_compare_active = true;
}
QTAILQ_INSERT_TAIL(&net_compares, s, next);
qemu_mutex_unlock(&colo_compare_mutex);
s->out_sendco.s = s;
s->out_sendco.chr = &s->chr_out;
@ -1292,9 +1308,6 @@ static void colo_compare_complete(UserCreatable *uc, Error **errp)
g_queue_init(&s->conn_list);
qemu_mutex_init(&event_mtx);
qemu_cond_init(&event_complete_cond);
s->connection_track_table = g_hash_table_new_full(connection_key_hash,
connection_key_equal,
g_free,
@ -1382,12 +1395,19 @@ static void colo_compare_finalize(Object *obj)
qemu_bh_delete(s->event_bh);
qemu_mutex_lock(&colo_compare_mutex);
QTAILQ_FOREACH(tmp, &net_compares, next) {
if (tmp == s) {
QTAILQ_REMOVE(&net_compares, s, next);
break;
}
}
if (QTAILQ_EMPTY(&net_compares)) {
colo_compare_active = false;
qemu_mutex_destroy(&event_mtx);
qemu_cond_destroy(&event_complete_cond);
}
qemu_mutex_unlock(&colo_compare_mutex);
AioContext *ctx = iothread_get_aio_context(s->iothread);
aio_context_acquire(ctx);
@ -1415,15 +1435,18 @@ static void colo_compare_finalize(Object *obj)
object_unref(OBJECT(s->iothread));
}
qemu_mutex_destroy(&event_mtx);
qemu_cond_destroy(&event_complete_cond);
g_free(s->pri_indev);
g_free(s->sec_indev);
g_free(s->outdev);
g_free(s->notify_dev);
}
static void __attribute__((__constructor__)) colo_compare_init_globals(void)
{
colo_compare_active = false;
qemu_mutex_init(&colo_compare_mutex);
}
static const TypeInfo colo_compare_info = {
.name = TYPE_COLO_COMPARE,
.parent = TYPE_OBJECT,