From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
wait_for_completion() may sleep, it enables interrupts and this
is something we really want to avoid on crashes because interrupt
handlers can cause other crashes. Switch to the recently introduced
vmbus_wait_for_unload() doing busy wait instead.
Reported-by: Radim Krcmar <rkrcmar@xxxxxxxxxx>
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Reviewed-by: Radim Kr.má<rkrcmar@xxxxxxxxxx>
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
---
drivers/hv/channel_mgmt.c | 4 ++--
drivers/hv/connection.c | 2 +-
drivers/hv/hyperv_vmbus.h | 2 +-
drivers/hv/vmbus_drv.c | 4 ++--
4 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index b40f429..f70e352 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -641,7 +641,7 @@ static void vmbus_unload_response(struct vmbus_channel_message_header *hdr)
complete(&vmbus_connection.unload_event);
}
-void vmbus_initiate_unload(void)
+void vmbus_initiate_unload(bool crash)
{
struct vmbus_channel_message_header hdr;
@@ -658,7 +658,7 @@ void vmbus_initiate_unload(void)
* vmbus_initiate_unload() is also called on crash and the crash can be
* happening in an interrupt context, where scheduling is impossible.
*/
- if (!in_interrupt())
+ if (!crash)
wait_for_completion(&vmbus_connection.unload_event);
else
vmbus_wait_for_unload();
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index fa86b2c..3b6dc00 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -236,7 +236,7 @@ void vmbus_disconnect(void)
/*
* First send the unload request to the host.
*/
- vmbus_initiate_unload();
+ vmbus_initiate_unload(false);
if (vmbus_connection.work_queue) {
drain_workqueue(vmbus_connection.work_queue);
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index b9ea7f5..b0299da 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -663,7 +663,7 @@ void hv_vss_onchannelcallback(void *);
int hv_fcopy_init(struct hv_util_service *);
void hv_fcopy_deinit(void);
void hv_fcopy_onchannelcallback(void *);
-void vmbus_initiate_unload(void);
+void vmbus_initiate_unload(bool crash);
static inline void hv_poll_channel(struct vmbus_channel *channel,
void (*cb)(void *))
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 30ea8ad..c8f1671 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1291,7 +1291,7 @@ static void hv_kexec_handler(void)
int cpu;
hv_synic_clockevents_cleanup();
- vmbus_initiate_unload();
+ vmbus_initiate_unload(false);
for_each_online_cpu(cpu)
smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
hv_cleanup();
@@ -1299,7 +1299,7 @@ static void hv_kexec_handler(void)
static void hv_crash_handler(struct pt_regs *regs)
{
- vmbus_initiate_unload();
+ vmbus_initiate_unload(true);
/*
* In crash handler we can't schedule synic cleanup for all CPUs,
* doing the cleanup for current CPU only. This should be sufficient
--
1.7.4.1
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