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authorAsias He <asias@redhat.com>2012-05-03 10:20:51 +0800
committerRusty Russell <rusty@rustcorp.com.au>2012-05-22 12:16:12 +0930
commit90e03207f468e84258270ad07095ef50f925c17d (patch)
treeb0a32e83e72f07064b9ae7156ec2bdc501734b6d
parentc877bab5072c8f461397949babbac10e348ae70d (diff)
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 <asias@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
-rw-r--r--drivers/virtio/virtio.c11
1 files changed, 9 insertions, 2 deletions
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 <linux/spinlock.h>
#include <linux/virtio_config.h>
#include <linux/module.h>
+#include <linux/idr.h>
/* 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);