xen/pciback: Fine-grain the spinlocks and fix BUG: scheduling while atomic cases.
We were using coarse spinlocks that could end up with a deadlock.
This patch fixes that and makes the spinlocks much more fine-grained.
We also drop be->watchding state spinlocks as they are already
guarded by the xenwatch_thread against multiple customers. Without
that we would trigger the BUG: scheduling while atomic.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/xen/xen-pciback/passthrough.c b/drivers/xen/xen-pciback/passthrough.c
index 5386bebf..6e3999b 100644
--- a/drivers/xen/xen-pciback/passthrough.c
+++ b/drivers/xen/xen-pciback/passthrough.c
@@ -113,14 +113,14 @@
{
int err = 0;
struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
- struct pci_dev_entry *dev_entry, *e;
+ struct pci_dev_entry *dev_entry, *e, *tmp;
struct pci_dev *dev;
int found;
unsigned int domain, bus;
spin_lock(&dev_data->lock);
- list_for_each_entry(dev_entry, &dev_data->dev_list, list) {
+ list_for_each_entry_safe(dev_entry, tmp, &dev_data->dev_list, list) {
/* Only publish this device as a root if none of its
* parent bridges are exported
*/
@@ -139,13 +139,16 @@
bus = (unsigned int)dev_entry->dev->bus->number;
if (!found) {
+ spin_unlock(&dev_data->lock);
err = publish_root_cb(pdev, domain, bus);
if (err)
break;
+ spin_lock(&dev_data->lock);
}
}
- spin_unlock(&dev_data->lock);
+ if (!err)
+ spin_unlock(&dev_data->lock);
return err;
}