[PATCH 3.12 54/86] Drivers: hv: get rid of timeout in vmbus_open()

From: Jiri Slaby
Date: Thu May 04 2017 - 05:15:33 EST


From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

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@xxxxxxxxxx>
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Signed-off-by: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/hv/channel.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 8cddbd10dadb..6f1731573097 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -114,7 +114,7 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
struct vmbus_channel_msginfo *open_info = NULL;
void *in, *out;
unsigned long flags;
- int ret, t, err = 0;
+ int ret, err = 0;

spin_lock_irqsave(&newchannel->sc_lock, flags);
if (newchannel->state == CHANNEL_OPEN_STATE) {
@@ -213,11 +213,7 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
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);


if (open_info->response.open_result.status)
--
2.12.2