cachefiles: cancel all requests for the object that is being dropped

Because after an object is dropped, requests for that object are useless,
cancel them to avoid causing other problems.

This prepares for the later addition of cancel_work_sync(). After the
reopen requests is generated, cancel it to avoid cancel_work_sync()
blocking by waiting for daemon to complete the reopen requests.

Signed-off-by: Baokun Li <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Acked-by: Jeff Layton <[email protected]>
Reviewed-by: Gao Xiang <[email protected]>
Reviewed-by: Jia Zhu <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

Author: LiBaokun96

fs/cachefiles/ondemand.c

@@ -564,12 +564,31 @@ int cachefiles_ondemand_init_object(struct cachefiles_object *object)
 
 void cachefiles_ondemand_clean_object(struct cachefiles_object *object)
 {
+	unsigned long index;
+	struct cachefiles_req *req;
+	struct cachefiles_cache *cache;
+
 	if (!object->ondemand)
 		return;
 
 	cachefiles_ondemand_send_req(object, CACHEFILES_OP_CLOSE, 0,
 			cachefiles_ondemand_init_close_req, NULL);
+
+	if (!object->ondemand->ondemand_id)
+		return;
+
+	/* Cancel all requests for the object that is being dropped. */
+	cache = object->volume->cache;
+	xa_lock(&cache->reqs);
 	cachefiles_ondemand_set_object_dropping(object);
+	xa_for_each(&cache->reqs, index, req) {
+		if (req->object == object) {
+			req->error = -EIO;
+			complete(&req->done);
+			__xa_erase(&cache->reqs, index);
+		}
+	}
+	xa_unlock(&cache->reqs);
 }
 
 int cachefiles_ondemand_init_obj_info(struct cachefiles_object *object,