Drivers: hv: vmbus: Prevent sending data on a rescinded channel

After the channel is rescinded, the host does not read from the rescinded channel.
Fail writes to a channel that has already been rescinded. If we permit writes on a
rescinded channel, since the host will not respond we will have situations where
we will be unable to unload vmbus drivers that cannot have any outstanding requests
to the host at the point they are unoaded.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
K. Y. Srinivasan 2016-12-07 01:16:28 -08:00 committed by Greg Kroah-Hartman
parent 56ef6718a1
commit e7e97dd8b7

View file

@ -298,6 +298,9 @@ int hv_ringbuffer_write(struct vmbus_channel *channel,
unsigned long flags = 0;
struct hv_ring_buffer_info *outring_info = &channel->outbound;
if (channel->rescind)
return -ENODEV;
for (i = 0; i < kv_count; i++)
totalbytes_towrite += kv_list[i].iov_len;
@ -350,6 +353,10 @@ int hv_ringbuffer_write(struct vmbus_channel *channel,
spin_unlock_irqrestore(&outring_info->ring_lock, flags);
hv_signal_on_write(old_write, channel, kick_q);
if (channel->rescind)
return -ENODEV;
return 0;
}