[3.11.y.z extended stable] Patch "virtio-scsi: avoid cancelling uninitialized work items" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    virtio-scsi: avoid cancelling uninitialized work items

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 674dd6914bd57347f98c23ea67567907ad370ec9 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini at redhat.com>
Date: Wed, 4 Jun 2014 13:34:56 +0200
Subject: virtio-scsi: avoid cancelling uninitialized work items

commit cdda0e5acbb78f7b777049f8c27899e5c5bb368f upstream.

Calling the workqueue interface on uninitialized work items isn't a
good idea even if they're zeroed. It's not failing catastrophically only
through happy accidents.

Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha at redhat.com>
Signed-off-by: Christoph Hellwig <hch at lst.de>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/scsi/virtio_scsi.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 95a5d73e675c..57c39e1e6681 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -288,6 +288,8 @@ static void virtscsi_ctrl_done(struct virtqueue *vq)
 	virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free);
 };

+static void virtscsi_handle_event(struct work_struct *work);
+
 static int virtscsi_kick_event(struct virtio_scsi *vscsi,
 			       struct virtio_scsi_event_node *event_node)
 {
@@ -295,6 +297,7 @@ static int virtscsi_kick_event(struct virtio_scsi *vscsi,
 	struct scatterlist sg;
 	unsigned long flags;

+	INIT_WORK(&event_node->work, virtscsi_handle_event);
 	sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));

 	spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
@@ -412,7 +415,6 @@ static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf)
 {
 	struct virtio_scsi_event_node *event_node = buf;

-	INIT_WORK(&event_node->work, virtscsi_handle_event);
 	schedule_work(&event_node->work);
 }

--
1.9.1