From 45942b79b9f89b42a5f5ccfa861c36a86a95d89a Mon Sep 17 00:00:00 2001 From: Lukas Straub Date: Fri, 22 May 2020 15:53:55 +0800 Subject: 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 Tested-by: Lukas Straub Reviewed-by: Zhang Chen Signed-off-by: Zhang Chen Signed-off-by: Jason Wang --- net/colo-compare.c | 35 +++++++++++++++++++++++++++++------ 1 file changed, 29 insertions(+), 6 deletions(-) diff --git a/net/colo-compare.c b/net/colo-compare.c index a609f49..c30dbfb 100644 --- a/net/colo-compare.c +++ b/net/colo-compare.c @@ -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, -- cgit v1.1