diff options
| author | Asias He <asias@redhat.com> | 2012-05-03 10:20:51 +0800 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2012-05-22 12:16:12 +0930 |
| commit | 90e03207f468e84258270ad07095ef50f925c17d (patch) | |
| tree | b0a32e83e72f07064b9ae7156ec2bdc501734b6d /drivers/virtio/virtio.c | |
| parent | c877bab5072c8f461397949babbac10e348ae70d (diff) | |
| download | lwn-90e03207f468e84258270ad07095ef50f925c17d.tar.gz lwn-90e03207f468e84258270ad07095ef50f925c17d.zip | |
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>
Diffstat (limited to 'drivers/virtio/virtio.c')
| -rw-r--r-- | drivers/virtio/virtio.c | 11 |
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); |