On 2018/7/10 0:40, Mike Christie wrote:
On 07/06/2018 08:47 PM, Xiubo Li wrote:
On 2018/7/7 2:58, Mike Christie wrote:
On 07/05/2018 09:57 PM, xiu...@redhat.com wrote:
void uio_event_notify(struct uio_info *info)
{
- struct uio_device *idev = info->uio_dev;
+ struct uio_device *idev;
+
+ if (!info)
+ return;
+
+ idev = info->uio_dev;
For this one too, I am not sure if it is needed.
uio_interrupt -> uio_event_notify. See other mail.
driver XYZ -> uio_event_notify. I think drivers need to handle this and
set some bits and/or perform some cleanup to make sure they are not
calling uio_event_notify after it has called uio_unregister_device. The
problem with the above test is if they do not they could have called
uio_unregister_device right after the info test so you could still hit
the problem.
When we are tcmu_destroy_device(), if the netlink notify event to
userspace is not successful then the TCMU will call the uio unregister,
which will set the idev->info = NULL, without close and deleting the
device in userspace. But the TCMU could still queue cmds to the ring
buffer, then the uio_event_notify will be called.
Before tcmu_destroy_device is called LIO will have stopped new IO and
waited for outstanding IO to be completed, so it would never be called
after uio_unregister_device. If it does, it's a bug in LIO.
Yeah, So this should be fixed now. Only hit one crash seem related to
uio of this code with lower kernel before.
Thanks,
BRs
