Drivers: hv: vmbus: Prevent sending data on a rescinded channel

commit e7e97dd8b77ee7366f2f8c70a033bf5fa05ec2e0 upstream.

After the channel is rescinded, the host does not read from the rescinded channel.
Fail writes to a channel that has already been rescinded.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rescinded channel, since the host will not respond we will have situations where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>
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 664f72a17f
commit e44eab51e7

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;
}