Drivers: hv: vmbus: Cleanup vmbus_close_internal()

commit 98d731bb064a9d1817a6ca9bf8b97051334a7cfe upstream.

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>
Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 0082155..72c08e9 100644 (file)
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -471,7 +471,7 @@ post_msg_err:
 }
 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 
-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;
@@ -493,11 +493,28 @@ 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);
@@ -506,7 +523,7 @@ 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;
 }
 
 /*