[PATCH 4.4 10/28] Drivers: hv: get rid of timeout in vmbus_open()

Greg Kroah-Hartman
2017-04-25T15:09:43Z

From: Vitaly Kuznetsov <vkuznets@redhat.com>

commit 396e287fa2ff46e83ae016cdcb300c3faa3b02f6 upstream.

vmbus_teardown_gpadl() can result in infinite wait when it is called on 5
second timeout in vmbus_open(). The issue is caused by the fact that gpadl
teardown operation won't ever succeed for an opened channel and the timeout
isn't always enough. As a guest, we can always trust the host to respond to
our request (and there is nothing we can do if it doesn't).

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/hv/channel.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)

--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -73,7 +73,6 @@ int vmbus_open(struct vmbus_channel *new
void *in, *out;
unsigned long flags;
int ret, err = 0;
- unsigned long t;
struct page *page;

spin_lock_irqsave(&newchannel->lock, flags);
@@ -183,11 +182,7 @@ int vmbus_open(struct vmbus_channel *new
goto error1;
}

- t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
- if (t == 0) {
- err = -ETIMEDOUT;
- goto error1;
- }
+ wait_for_completion(&open_info->waitevent);

spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_del(&open_info->msglistentry);