Drivers: hv: vmbus: Cleanup vmbus_close_internal()

Eliminate calls to BUG_ON() in vmbus_close_internal().
We have chosen to potentially leak memory, than crash the guest
in case of failures.

In this version of the patch I have addressed comments from
Dan Carpenter (dan.carpenter@oracle.com).

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 23 insertions, 6 deletions

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index b4eebe34ca91..19bad59073e6 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -478,7 +478,7 @@ static void reset_channel_cb(void *arg)
         channel->onchannel_callback = NULL;
 }
 
-static void vmbus_close_internal(struct vmbus_channel *channel)
+static int vmbus_close_internal(struct vmbus_channel *channel)
 {
         struct vmbus_channel_close_channel *msg;
         int ret;
@@ -501,11 +501,28 @@ static void vmbus_close_internal(struct vmbus_channel *channel)
 
         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
 
-        BUG_ON(ret != 0);
+        if (ret) {
+                pr_err("Close failed: close post msg return is %d\n", ret);
+                /*
+                 * If we failed to post the close msg,
+                 * it is perhaps better to leak memory.
+                 */
+                return ret;
+        }
+
         /* Tear down the gpadl for the channel's ring buffer */
-        if (channel->ringbuffer_gpadlhandle)
-                vmbus_teardown_gpadl(channel,
-                                          channel->ringbuffer_gpadlhandle);
+        if (channel->ringbuffer_gpadlhandle) {
+                ret = vmbus_teardown_gpadl(channel,
+                                           channel->ringbuffer_gpadlhandle);
+                if (ret) {
+                        pr_err("Close failed: teardown gpadl return %d\n", ret);
+                        /*
+                         * If we failed to teardown gpadl,
+                         * it is perhaps better to leak memory.
+                         */
+                        return ret;
+                }
+        }
 
         /* Cleanup the ring buffers for this channel */
         hv_ringbuffer_cleanup(&channel->outbound);
@@ -514,7 +531,7 @@ static void vmbus_close_internal(struct vmbus_channel *channel)
         free_pages((unsigned long)channel->ringbuffer_pages,
                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 
-
+        return ret;
 }
 
 /*