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authorDexuan Cui <decui@microsoft.com>2019-09-05 23:01:20 +0000
committerSasha Levin <sashal@kernel.org>2019-09-06 14:52:44 -0400
commit1f48dcf180e5422b1a633b24680dd0f5c3f540f5 (patch)
tree20d79f9ecaf990857ec86829d38b89b8e39724f6 /drivers/hv
parentf53335e3289f9ac3a6a8faf6c2f819eee508bd39 (diff)
downloadlinux-next-1f48dcf180e5422b1a633b24680dd0f5c3f540f5.tar.gz
Drivers: hv: vmbus: Clean up hv_sock channels by force upon suspend
Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for hibernation. There is no better method to clean up the channels since some of the channels may still be referenced by the userspace apps when hibernation is triggered: in this case, with this patch, the "rescind" fields of the channels are set, and the apps will thoroughly destroy the channels after hibernation. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/hv')
-rw-r--r--drivers/hv/vmbus_drv.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index ce9974bf683f..45b976ec6e79 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -24,6 +24,7 @@
#include <linux/sched/task_stack.h>
#include <asm/mshyperv.h>
+#include <linux/delay.h>
#include <linux/notifier.h>
#include <linux/ptrace.h>
#include <linux/screen_info.h>
@@ -1069,6 +1070,41 @@ msg_handled:
vmbus_signal_eom(msg, message_type);
}
+/*
+ * Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for
+ * hibernation, because hv_sock connections can not persist across hibernation.
+ */
+static void vmbus_force_channel_rescinded(struct vmbus_channel *channel)
+{
+ struct onmessage_work_context *ctx;
+ struct vmbus_channel_rescind_offer *rescind;
+
+ WARN_ON(!is_hvsock_channel(channel));
+
+ /*
+ * sizeof(*ctx) is small and the allocation should really not fail,
+ * otherwise the state of the hv_sock connections ends up in limbo.
+ */
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL | __GFP_NOFAIL);
+
+ /*
+ * So far, these are not really used by Linux. Just set them to the
+ * reasonable values conforming to the definitions of the fields.
+ */
+ ctx->msg.header.message_type = 1;
+ ctx->msg.header.payload_size = sizeof(*rescind);
+
+ /* These values are actually used by Linux. */
+ rescind = (struct vmbus_channel_rescind_offer *)ctx->msg.u.payload;
+ rescind->header.msgtype = CHANNELMSG_RESCIND_CHANNELOFFER;
+ rescind->child_relid = channel->offermsg.child_relid;
+
+ INIT_WORK(&ctx->work, vmbus_onmessage_work);
+
+ queue_work_on(vmbus_connection.connect_cpu,
+ vmbus_connection.work_queue,
+ &ctx->work);
+}
/*
* Direct callback for channels using other deferred processing
@@ -2091,6 +2127,25 @@ acpi_walk_err:
static int vmbus_bus_suspend(struct device *dev)
{
+ struct vmbus_channel *channel;
+
+ while (atomic_read(&vmbus_connection.offer_in_progress) != 0) {
+ /*
+ * We wait here until the completion of any channel
+ * offers that are currently in progress.
+ */
+ msleep(1);
+ }
+
+ mutex_lock(&vmbus_connection.channel_mutex);
+ list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
+ if (!is_hvsock_channel(channel))
+ continue;
+
+ vmbus_force_channel_rescinded(channel);
+ }
+ mutex_unlock(&vmbus_connection.channel_mutex);
+
vmbus_initiate_unload(false);
vmbus_connection.conn_state = DISCONNECTED;