[GIT PULL] SCSI fixes for 4.10-rc6

From: James Bottomley
Date: Fri Feb 03 2017 - 16:17:20 EST


A single fix this time: a fix for a virtqueue removal bug which only
appears to affect S390, but which results in the queue hanging forever
thus causing the machine to fail shutdown.

The patch is available here:

git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git scsi-fixes

The short changelog is:

Eric Farman (1):
scsi: virtio_scsi: Reject commands when virtqueue is broken

And the diffstat:

drivers/scsi/virtio_scsi.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

With full diff below.

James

---

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index ec91bd0..c680d76 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -534,7 +534,9 @@ static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
{
struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc);
+ unsigned long flags;
int req_size;
+ int ret;

BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);

@@ -562,8 +564,15 @@ static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
req_size = sizeof(cmd->req.cmd);
}

- if (virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd)) != 0)
+ ret = virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd));
+ if (ret == -EIO) {
+ cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
+ spin_lock_irqsave(&req_vq->vq_lock, flags);
+ virtscsi_complete_cmd(vscsi, cmd);
+ spin_unlock_irqrestore(&req_vq->vq_lock, flags);
+ } else if (ret != 0) {
return SCSI_MLQUEUE_HOST_BUSY;
+ }
return 0;
}