From: Asias He Date: Thu, 3 May 2012 02:20:51 +0000 (+0800) Subject: virtio: Use ida to allocate virtio index X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=90e03207f468e84258270ad07095ef50f925c17d;p=openwrt%2Fstaging%2Fblogic.git virtio: Use ida to allocate virtio index Current index allocation in virtio is based on a monotonically increasing variable "index". This means we'll run out of numbers after a while. E.g. someone crazy doing this in host side. while(1) { hot-plug a virtio device hot-unplug the virito devcie } Signed-off-by: Asias He Signed-off-by: Rusty Russell --- diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index 984c501c258f..f3558070e375 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -2,9 +2,10 @@ #include #include #include +#include /* Unique numbering for virtio devices. */ -static unsigned int dev_index; +static DEFINE_IDA(virtio_index_ida); static ssize_t device_show(struct device *_d, struct device_attribute *attr, char *buf) @@ -193,7 +194,11 @@ int register_virtio_device(struct virtio_device *dev) dev->dev.bus = &virtio_bus; /* Assign a unique device index and hence name. */ - dev->index = dev_index++; + err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL); + if (err < 0) + goto out; + + dev->index = err; dev_set_name(&dev->dev, "virtio%u", dev->index); /* We always start by resetting the device, in case a previous @@ -208,6 +213,7 @@ int register_virtio_device(struct virtio_device *dev) /* device_register() causes the bus infrastructure to look for a * matching driver. */ err = device_register(&dev->dev); +out: if (err) add_status(dev, VIRTIO_CONFIG_S_FAILED); return err; @@ -217,6 +223,7 @@ EXPORT_SYMBOL_GPL(register_virtio_device); void unregister_virtio_device(struct virtio_device *dev) { device_unregister(&dev->dev); + ida_simple_remove(&virtio_index_ida, dev->index); } EXPORT_SYMBOL_GPL(unregister_virtio_device);