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From: "K. Y. Srinivasan" <kys@microsoft.com>
To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
	devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com,
	jasowang@redhat.com, sitsofe@gmail.com, decui@microsoft.com
Cc: "K. Y. Srinivasan" <kys@microsoft.com>, <stable@vger.kernel.org>
Subject: [PATCH V3 3/5] Drivers: hv: vmbus: Cleanup vmbus_close_internal()
Date: Wed, 27 Aug 2014 16:25:33 -0700	[thread overview]
Message-ID: <1409181935-23295-3-git-send-email-kys@microsoft.com> (raw)
In-Reply-To: <1409181935-23295-1-git-send-email-kys@microsoft.com>

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>
---
 drivers/hv/channel.c |   29 +++++++++++++++++++++++------
 1 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 0206314..eb3158e 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -479,7 +479,7 @@ 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;
@@ -502,11 +502,28 @@ 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);
@@ -515,7 +532,7 @@ 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;
 }
 
 /*
-- 
1.7.4.1


  parent reply	other threads:[~2014-08-27 22:22 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-27 23:25 [PATCH V2 0/5] Drivers: hv: vmbus: Eliminate calls to BUG_ON() K. Y. Srinivasan
2014-08-27 23:25 ` [PATCH V2 1/5] Drivers: hv: vmbus: Cleanup vmbus_post_msg() K. Y. Srinivasan
2014-08-27 23:25   ` [PATCH V2 2/5] Drivers: hv: vmbus: Cleanup vmbus_teardown_gpadl() K. Y. Srinivasan
2014-08-27 23:25   ` K. Y. Srinivasan [this message]
2014-08-27 23:25   ` [PATCH V2 4/5] Drivers: hv: vmbus: Cleanup vmbus_establish_gpadl() K. Y. Srinivasan
2014-08-27 23:25   ` [PATCH V2 5/5] Drivers: hv: vmbus: Fix a bug in vmbus_open() K. Y. Srinivasan
2014-08-29  7:29 ` [PATCH V2 0/5] Drivers: hv: vmbus: Eliminate calls to BUG_ON() Sitsofe Wheeler
2014-09-15 18:39   ` KY Srinivasan
2014-09-23 18:41     ` KY Srinivasan

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