diff options
| -rw-r--r-- | drivers/hv/channel_mgmt.c | 12 | ||||
| -rw-r--r-- | include/linux/hyperv.h | 1 |
2 files changed, 13 insertions, 0 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index 4072fd1f2214..68950a1e4b63 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -1063,6 +1063,18 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) mutex_lock(&vmbus_connection.channel_mutex); channel = relid2channel(rescind->child_relid); + if (channel != NULL) { + /* + * Guarantee that no other instance of vmbus_onoffer_rescind() + * has got a reference to the channel object. Synchronize on + * &vmbus_connection.channel_mutex. + */ + if (channel->rescind_ref) { + mutex_unlock(&vmbus_connection.channel_mutex); + return; + } + channel->rescind_ref = true; + } mutex_unlock(&vmbus_connection.channel_mutex); if (channel == NULL) { diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 2ea967bc17ad..f0d48a368f13 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -809,6 +809,7 @@ struct vmbus_channel { u8 monitor_bit; bool rescind; /* got rescind msg */ + bool rescind_ref; /* got rescind msg, got channel reference */ struct completion rescind_event; u32 ringbuffer_gpadlhandle; |