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From: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
To: rusty@rustcorp.com.au, mst@redhat.com,
	virtualization@lists.linux-foundation.org
Cc: borntraeger@de.ibm.com
Subject: [PATCH V2 RFC 8/9] virtio_net: verify if queue is broken after virtqueue_get_buf()
Date: Thu, 24 Oct 2013 17:23:19 +0200	[thread overview]
Message-ID: <1382628200-42956-9-git-send-email-graalfs@linux.vnet.ibm.com> (raw)
In-Reply-To: <1382628200-42956-1-git-send-email-graalfs@linux.vnet.ibm.com>

If a virtqueue_get_buf() call returns a NULL pointer a possibly endless while
loop should be avoided by checking for a broken virtqueue.

Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
---
 drivers/net/virtio_net.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 6584e3a..f092b9d 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -802,7 +802,8 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
 	/* Spin for a response, the kick causes an ioport write, trapping
 	 * into the hypervisor, so the request should be handled immediately.
 	 */
-	while (!virtqueue_get_buf(vi->cvq, &tmp))
+	while (!virtqueue_get_buf(vi->cvq, &tmp) &&
+	       !virtqueue_is_broken(vi->cvq))
 		cpu_relax();
 
 	return status == VIRTIO_NET_OK;
-- 
1.8.3.1

  parent reply	other threads:[~2013-10-24 15:23 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-24 15:23 [PATCH V2 RFC 0/9] virtio: fix hang(loop) after hot-unplug vlan Heinz Graalfs
2013-10-24 15:23 ` [PATCH V2 RFC 1/9] virtio_ring: change host notification API Heinz Graalfs
2013-10-27 23:27   ` Rusty Russell
2013-10-24 15:23 ` [PATCH V2 RFC 2/9] virtio_ring: let virtqueue_{kick()/notify()} return a bool Heinz Graalfs
2013-10-24 15:23 ` [PATCH V2 RFC 3/9] virtio_net: verify if virtqueue_kick() succeeded Heinz Graalfs
2013-10-24 15:23 ` [PATCH V2 RFC 4/9] virtio_test: " Heinz Graalfs
2013-10-24 15:23 ` [PATCH V2 RFC 5/9] virtio_ring: add new function virtqueue_is_broken() Heinz Graalfs
2013-10-24 15:23 ` [PATCH V2 RFC 6/9] virtio_blk: verify if queue is broken after virtqueue_get_buf() Heinz Graalfs
2013-10-24 15:23 ` [PATCH V2 RFC 7/9] virtio_console: " Heinz Graalfs
2013-10-24 15:23 ` Heinz Graalfs [this message]
2013-10-24 15:23 ` [PATCH V2 RFC 9/9] virtio_scsi: " Heinz Graalfs
2013-10-27 23:29   ` Rusty Russell
2013-10-29  1:04   ` Rusty Russell

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