From: Naman Jain <namjain@xxxxxxxxxxxxxxxxxxx> Sent: Sunday, August 25, 2024 10:32 PM > > On 8/25/2024 8:27 AM, Michael Kelley wrote: > > From: Naman Jain <namjain@xxxxxxxxxxxxxxxxxxx> Sent: Thursday, August 22, 2024 4:09 AM > >> > >> Rescind offer handling relies on rescind callbacks for some of the > >> resources cleanup, if they are registered. It does not unregister > >> vmbus device for the primary channel closure, when callback is > >> registered. > >> Add logic to unregister vmbus for the primary channel in rescind callback > >> to ensure channel removal and relid release, and to ensure rescind flag > >> is false when driver probe happens again. > >> > >> Fixes: ca3cda6fcf1e ("uio_hv_generic: add rescind support") > >> Signed-off-by: Naman Jain <namjain@xxxxxxxxxxxxxxxxxxx> > >> --- > >> drivers/hv/vmbus_drv.c | 1 + > >> drivers/uio/uio_hv_generic.c | 7 +++++++ > >> 2 files changed, 8 insertions(+) > >> > >> diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c > >> index c857dc3975be..4bae382a3eb4 100644 > >> --- a/drivers/hv/vmbus_drv.c > >> +++ b/drivers/hv/vmbus_drv.c > >> @@ -1952,6 +1952,7 @@ void vmbus_device_unregister(struct hv_device *device_obj) > >> */ > >> device_unregister(&device_obj->device); > >> } > >> +EXPORT_SYMBOL_GPL(vmbus_device_unregister); > >> > >> #ifdef CONFIG_ACPI > >> /* > >> diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c > >> index c99890c16d29..ea26c0b460d6 100644 > >> --- a/drivers/uio/uio_hv_generic.c > >> +++ b/drivers/uio/uio_hv_generic.c > >> @@ -121,6 +121,13 @@ static void hv_uio_rescind(struct vmbus_channel *channel) > >> > >> /* Wake up reader */ > >> uio_event_notify(&pdata->info); > >> + > >> + /* > >> + * With rescind callback registered, rescind path will not unregister the device > >> + * when the primary channel is rescinded. Without it, next onoffer msg does not come. > >> + */ > >> + if (!channel->primary_channel) > >> + vmbus_device_unregister(channel->device_obj); > > > > When the rescind callback is *not* set, vmbus_onoffer_rescind() makes the > > call to vmbus_device_unregister(). But it does so bracketed with get_device()/ > > put_device(). Your code here does not do the bracketing. Is there a reason for > > the difference? Frankly, I'm not sure why vmbus_onoffer_rescind() does the > > bracketing, and I can't definitively say if it is really needed. So I guess I'm > > just asking if you know. :-) > > > > Michael > > IMHO, we have already NULL checked channel->device_obj and other couple > of things to make sure we are safe to clean this up. At other places as > well, I don't see the use of put and get device. So I think its not > required. I am open to suggestions. > > Regards, > Naman OK. I'm good with what you've said, and don't have any further suggestions. Go with what your patch already has. :-) Michael