From 3ee70591d6c47ef4c4699b3395ba96ce287db937 Mon Sep 17 00:00:00 2001 From: Jim Quigley Date: Fri, 21 Jul 2017 09:20:15 -0400 Subject: [PATCH] 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 Reviewed-by: Liam Merwick Reviewed-by: Shannon Nelson Reviewed-by: Alexandre Chartre Reviewed-by: Aaron Young Signed-off-by: David S. Miller --- drivers/block/sunvdc.c | 61 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) 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); -- 2.39.2