[PATCH 3.13 037/105] Drivers: hv: vmbus: Cleanup vmbus_close_internal()

Kamal Mostafa
2014-10-27T19:04:27Z

From: "K. Y. Srinivasan" <kys@microsoft.com>

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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
drivers/hv/channel.c | 29 +++++++++++++++++++++++------
1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index dd6ba42..cf1e49b 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -468,7 +468,7 @@ 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;
@@ -490,11 +490,28 @@ 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);
@@ -503,7 +520,7 @@ 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;
}

/*
--
1.9.1