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authorJim Quigley <Jim.Quigley@oracle.com>2017-07-21 16:20:15 +0300
committerDavid S. Miller <davem@davemloft.net>2017-08-10 08:22:32 +0300
commit3ee70591d6c47ef4c4699b3395ba96ce287db937 (patch)
tree5af772dfe1a1bf7ec0d9d3436542463f056f47c4
parentfdaccf74fe83ab3438df014efd55788a1dd414b5 (diff)
downloadlinux-3ee70591d6c47ef4c4699b3395ba96ce287db937.tar.xz
sunvdc: prevent sunvdc panic when mpgroup disk added to guest domain
Using mpgroup to define multiple paths for a virtual disk causes multiple virtual-device-port ports to be created for that virtual device. Each virtual-device-port port then gets a vdisk created for it by the Linux sunvdc driver. As mpgroup is not supported by the Linux sunvdc driver it cannot handle multiple ports for a single vdisk, leading to a kernel panic at startup. This fix prevents more than one vdisk per virtual-device-port being created until full virtual disk multipathing (mpgroup) support is implemented. Signed-off-by: Jim Quigley <Jim.Quigley@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Aaron Young <aaron.young@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/block/sunvdc.c61
1 files changed, 61 insertions, 0 deletions
diff --git a/drivers/block/sunvdc.c b/drivers/block/sunvdc.c
index 6b16ead1da58..ad9749463d4f 100644
--- a/drivers/block/sunvdc.c
+++ b/drivers/block/sunvdc.c
@@ -875,6 +875,56 @@ static void print_version(void)
printk(KERN_INFO "%s", version);
}
+struct vdc_check_port_data {
+ int dev_no;
+ char *type;
+};
+
+static int vdc_device_probed(struct device *dev, void *arg)
+{
+ struct vio_dev *vdev = to_vio_dev(dev);
+ struct vdc_check_port_data *port_data;
+
+ port_data = (struct vdc_check_port_data *)arg;
+
+ if ((vdev->dev_no == port_data->dev_no) &&
+ (!(strcmp((char *)&vdev->type, port_data->type))) &&
+ dev_get_drvdata(dev)) {
+ /* This device has already been configured
+ * by vdc_port_probe()
+ */
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+/* Determine whether the VIO device is part of an mpgroup
+ * by locating all the virtual-device-port nodes associated
+ * with the parent virtual-device node for the VIO device
+ * and checking whether any of these nodes are vdc-ports
+ * which have already been configured.
+ *
+ * Returns true if this device is part of an mpgroup and has
+ * already been probed.
+ */
+static bool vdc_port_mpgroup_check(struct vio_dev *vdev)
+{
+ struct vdc_check_port_data port_data;
+ struct device *dev;
+
+ port_data.dev_no = vdev->dev_no;
+ port_data.type = (char *)&vdev->type;
+
+ dev = device_find_child(vdev->dev.parent, &port_data,
+ vdc_device_probed);
+
+ if (dev)
+ return true;
+
+ return false;
+}
+
static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
{
struct mdesc_handle *hp;
@@ -893,6 +943,14 @@ static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
goto err_out_release_mdesc;
}
+ /* Check if this device is part of an mpgroup */
+ if (vdc_port_mpgroup_check(vdev)) {
+ printk(KERN_WARNING
+ "VIO: Ignoring extra vdisk port %s",
+ dev_name(&vdev->dev));
+ goto err_out_release_mdesc;
+ }
+
port = kzalloc(sizeof(*port), GFP_KERNEL);
err = -ENOMEM;
if (!port) {
@@ -943,6 +1001,9 @@ static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
if (err)
goto err_out_free_tx_ring;
+ /* Note that the device driver_data is used to determine
+ * whether the port has been probed.
+ */
dev_set_drvdata(&vdev->dev, port);
mdesc_release(hp);