RDMA/uverbs: Move IB_EVENT_DEVICE_FATAL to destroy_uobj

When multiple async FDs were allowed to exist the idea was for all
broadcast events to be delivered to all async FDs, however
IB_EVENT_DEVICE_FATAL was missed.

Instead of having ib_uverbs_free_hw_resources() special case the global
async_fd, have it cause the event during the uobject destruction. Every
async fd is now a uobject so simply generate the IB_EVENT_DEVICE_FATAL
while destroying the async fd uobject. This ensures every async FD gets a
copy of the event.

Fixes: d680e88 ("RDMA/core: Add UVERBS_METHOD_ASYNC_EVENT_ALLOC")
Link: https://lore.kernel.org/r/20200507063348.98713-3-leon@kernel.org
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/uverbs.h

@@ -228,6 +228,9 @@ void ib_uverbs_release_ucq(struct ib_uverbs_completion_event_file *ev_file,
 			   struct ib_ucq_object *uobj);
 void ib_uverbs_release_uevent(struct ib_uevent_object *uobj);
 void ib_uverbs_release_file(struct kref *ref);
+void ib_uverbs_async_handler(struct ib_uverbs_async_event_file *async_file,
+			     __u64 element, __u64 event,
+			     struct list_head *obj_list, u32 *counter);
 
 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context);
 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr);

drivers/infiniband/core/uverbs_main.c

@@ -386,10 +386,9 @@ void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
 	kill_fasync(&ev_queue->async_queue, SIGIO, POLL_IN);
 }
 
-static void
-ib_uverbs_async_handler(struct ib_uverbs_async_event_file *async_file,
-			__u64 element, __u64 event, struct list_head *obj_list,
-			u32 *counter)
+void ib_uverbs_async_handler(struct ib_uverbs_async_event_file *async_file,
+			     __u64 element, __u64 event,
+			     struct list_head *obj_list, u32 *counter)
 {
 	struct ib_uverbs_event *entry;
 	unsigned long flags;
@@ -1187,9 +1186,6 @@ static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
 		 */
 		mutex_unlock(&uverbs_dev->lists_mutex);
 
-		ib_uverbs_async_handler(READ_ONCE(file->async_file), 0,
-					IB_EVENT_DEVICE_FATAL, NULL, NULL);
-
 		uverbs_destroy_ufile_hw(file, RDMA_REMOVE_DRIVER_REMOVE);
 		kref_put(&file->ref, ib_uverbs_release_file);
 

drivers/infiniband/core/uverbs_std_types_async_fd.c

@@ -26,6 +26,10 @@ static int uverbs_async_event_destroy_uobj(struct ib_uobject *uobj,
 		container_of(uobj, struct ib_uverbs_async_event_file, uobj);
 
 	ib_unregister_event_handler(&event_file->event_handler);
+
+	if (why == RDMA_REMOVE_DRIVER_REMOVE)
+		ib_uverbs_async_handler(event_file, 0, IB_EVENT_DEVICE_FATAL,
+					NULL, NULL);
 	return 0;
 }