Drivers: hv: vmbus: Fix rescind handling in uio_hv_generic

commit 6fd2894 upstream. 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. Without it, next onoffer does not come, rescind flag remains set and device goes to unusable state. Add logic to unregister vmbus for the primary channel in rescind callback to ensure channel removal and relid release, and to ensure that next onoffer can be received and handled properly. Cc: [email protected] Fixes: ca3cda6 ("uio_hv_generic: add rescind support") Signed-off-by: Naman Jain <[email protected]> Reviewed-by: Saurabh Sengar <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
xanmod · Sep 12, 2024 · 6ed4574 · 6ed4574
1 parent de6946b
commit 6ed4574
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diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
@@ -1962,6 +1962,7 @@ 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
@@ -119,6 +119,14 @@ 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
+	 * from vmbus when the primary channel is rescinded.
+	 * Without it, rescind handling is incomplete and next onoffer msg does not come.
+	 * Unregister the device from vmbus here.
+	 */
+	vmbus_device_unregister(channel->device_obj);
 }
 
 /* Sysfs API to allow mmap of the ring buffers