fs: get rid of the res2 iocb->ki_complete argument

The second argument was only used by the USB gadget code, yet everyone
pays the overhead of passing a zero to be passed into aio, where it
ends up being part of the aio res2 value.

Now that everybody is passing in zero, kill off the extra argument.

Reviewed-by: Darrick J. Wong <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

block/fops.c

···
 				ret = blk_status_to_errno(dio->bio.bi_status);
 			}
 
-			dio->iocb->ki_complete(iocb, ret, 0);
+			dio->iocb->ki_complete(iocb, ret);
 			if (dio->flags & DIO_MULTI_BIO)
 				bio_put(&dio->bio);
 		} else {

crypto/af_alg.c

···
 	af_alg_free_resources(areq);
 	sock_put(sk);
 
-	iocb->ki_complete(iocb, err ? err : (int)resultlen, 0);
+	iocb->ki_complete(iocb, err ? err : (int)resultlen);
 }
 EXPORT_SYMBOL_GPL(af_alg_async_cb);
 

drivers/block/loop.c

···
 		blk_mq_complete_request(rq);
 }
 
-static void lo_rw_aio_complete(struct kiocb *iocb, long ret, long ret2)
+static void lo_rw_aio_complete(struct kiocb *iocb, long ret)
 {
 	struct loop_cmd *cmd = container_of(iocb, struct loop_cmd, iocb);
 
···
 	lo_rw_aio_do_completion(cmd);
 
 	if (ret != -EIOCBQUEUED)
-		cmd->iocb.ki_complete(&cmd->iocb, ret, 0);
+		lo_rw_aio_complete(&cmd->iocb, ret);
 	return 0;
 }
 

drivers/nvme/target/io-cmd-file.c

···
 	return call_iter(iocb, &iter);
 }
 
-static void nvmet_file_io_done(struct kiocb *iocb, long ret, long ret2)
+static void nvmet_file_io_done(struct kiocb *iocb, long ret)
 {
 	struct nvmet_req *req = container_of(iocb, struct nvmet_req, f.iocb);
 	u16 status = NVME_SC_SUCCESS;
···
 	}
 
 complete:
-	nvmet_file_io_done(&req->f.iocb, ret, 0);
+	nvmet_file_io_done(&req->f.iocb, ret);
 	return true;
 }
 

drivers/target/target_core_file.c

···
 	struct bio_vec	bvecs[];
 };
 
-static void cmd_rw_aio_complete(struct kiocb *iocb, long ret, long ret2)
+static void cmd_rw_aio_complete(struct kiocb *iocb, long ret)
 {
 	struct target_core_file_cmd *cmd;
 
···
 		ret = call_read_iter(file, &aio_cmd->iocb, &iter);
 
 	if (ret != -EIOCBQUEUED)
-		cmd_rw_aio_complete(&aio_cmd->iocb, ret, 0);
+		cmd_rw_aio_complete(&aio_cmd->iocb, ret);
 
 	return 0;
 }

drivers/usb/gadget/function/f_fs.c

···
 		kthread_unuse_mm(io_data->mm);
 	}
 
-	io_data->kiocb->ki_complete(io_data->kiocb, ret, 0);
+	io_data->kiocb->ki_complete(io_data->kiocb, ret);
 
 	if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd)
 		eventfd_signal(io_data->ffs->ffs_eventfd, 1);

drivers/usb/gadget/legacy/inode.c

···
 		ret = -EFAULT;
 
 	/* completing the iocb can drop the ctx and mm, don't touch mm after */
-	iocb->ki_complete(iocb, ret, 0);
+	iocb->ki_complete(iocb, ret);
 
 	kfree(priv->buf);
 	kfree(priv->to_free);
···
 		kfree(priv);
 		iocb->private = NULL;
 		iocb->ki_complete(iocb,
-				req->actual ? req->actual : (long)req->status,
-				0);
+				req->actual ? req->actual : (long)req->status);
 	} else {
 		/* ep_copy_to_user() won't report both; we hide some faults */
 		if (unlikely(0 != req->status))

fs/aio.c

···
 	spin_unlock_irqrestore(&ctx->ctx_lock, flags);
 }
 
-static void aio_complete_rw(struct kiocb *kiocb, long res, long res2)
+static void aio_complete_rw(struct kiocb *kiocb, long res)
 {
 	struct aio_kiocb *iocb = container_of(kiocb, struct aio_kiocb, rw);
 
···
 	}
 
 	iocb->ki_res.res = res;
-	iocb->ki_res.res2 = res2;
+	iocb->ki_res.res2 = 0;
 	iocb_put(iocb);
 }
 
···
 		ret = -EINTR;
 		fallthrough;
 	default:
-		req->ki_complete(req, ret, 0);
+		req->ki_complete(req, ret);
 	}
 }
 

fs/cachefiles/io.c

···
 /*
  * Handle completion of a read from the cache.
  */
-static void cachefiles_read_complete(struct kiocb *iocb, long ret, long ret2)
+static void cachefiles_read_complete(struct kiocb *iocb, long ret)
 {
 	struct cachefiles_kiocb *ki = container_of(iocb, struct cachefiles_kiocb, iocb);
 
-	_enter("%ld,%ld", ret, ret2);
+	_enter("%ld", ret);
 
 	if (ki->term_func) {
 		if (ret >= 0)
···
 		fallthrough;
 	default:
 		ki->was_async = false;
-		cachefiles_read_complete(&ki->iocb, ret, 0);
+		cachefiles_read_complete(&ki->iocb, ret);
 		if (ret > 0)
 			ret = 0;
 		break;
···
 /*
  * Handle completion of a write to the cache.
  */
-static void cachefiles_write_complete(struct kiocb *iocb, long ret, long ret2)
+static void cachefiles_write_complete(struct kiocb *iocb, long ret)
 {
 	struct cachefiles_kiocb *ki = container_of(iocb, struct cachefiles_kiocb, iocb);
 	struct inode *inode = file_inode(ki->iocb.ki_filp);
 
-	_enter("%ld,%ld", ret, ret2);
+	_enter("%ld", ret);
 
 	/* Tell lockdep we inherited freeze protection from submission thread */
 	__sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE);
···
 		fallthrough;
 	default:
 		ki->was_async = false;
-		cachefiles_write_complete(&ki->iocb, ret, 0);
+		cachefiles_write_complete(&ki->iocb, ret);
 		if (ret > 0)
 			ret = 0;
 		break;

fs/ceph/file.c

···
 	ceph_put_cap_refs(ci, (aio_req->write ? CEPH_CAP_FILE_WR :
 						CEPH_CAP_FILE_RD));
 
-	aio_req->iocb->ki_complete(aio_req->iocb, ret, 0);
+	aio_req->iocb->ki_complete(aio_req->iocb, ret);
 
 	ceph_free_cap_flush(aio_req->prealloc_cf);
 	kfree(aio_req);

fs/cifs/file.c

···
 	mutex_unlock(&ctx->aio_mutex);
 
 	if (ctx->iocb && ctx->iocb->ki_complete)
-		ctx->iocb->ki_complete(ctx->iocb, ctx->rc, 0);
+		ctx->iocb->ki_complete(ctx->iocb, ctx->rc);
 	else
 		complete(&ctx->done);
 }
···
 	mutex_unlock(&ctx->aio_mutex);
 
 	if (ctx->iocb && ctx->iocb->ki_complete)
-		ctx->iocb->ki_complete(ctx->iocb, ctx->rc, 0);
+		ctx->iocb->ki_complete(ctx->iocb, ctx->rc);
 	else
 		complete(&ctx->done);
 }

fs/direct-io.c

···
 
 		if (ret > 0 && dio->op == REQ_OP_WRITE)
 			ret = generic_write_sync(dio->iocb, ret);
-		dio->iocb->ki_complete(dio->iocb, ret, 0);
+		dio->iocb->ki_complete(dio->iocb, ret);
 	}
 
 	kmem_cache_free(dio_cache, dio);

fs/fuse/file.c

···
 			spin_unlock(&fi->lock);
 		}
 
-		io->iocb->ki_complete(io->iocb, res, 0);
+		io->iocb->ki_complete(io->iocb, res);
 	}
 
 	kref_put(&io->refcnt, fuse_io_release);

fs/io_uring.c

···
 	__io_req_complete(req, issue_flags, req->result, io_put_rw_kbuf(req));
 }
 
-static void io_complete_rw(struct kiocb *kiocb, long res, long res2)
+static void io_complete_rw(struct kiocb *kiocb, long res)
 {
 	struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
 
···
 	io_req_task_work_add(req);
 }
 
-static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2)
+static void io_complete_rw_iopoll(struct kiocb *kiocb, long res)
 {
 	struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
 
···
 		ret = -EINTR;
 		fallthrough;
 	default:
-		kiocb->ki_complete(kiocb, ret, 0);
+		kiocb->ki_complete(kiocb, ret);
 	}
 }
 

fs/iomap/direct-io.c

···
 	struct iomap_dio *dio = container_of(work, struct iomap_dio, aio.work);
 	struct kiocb *iocb = dio->iocb;
 
-	iocb->ki_complete(iocb, iomap_dio_complete(dio), 0);
+	iocb->ki_complete(iocb, iomap_dio_complete(dio));
 }
 
 /*

fs/nfs/direct.c

···
 			res = (long) dreq->count;
 			WARN_ON_ONCE(dreq->count < 0);
 		}
-		dreq->iocb->ki_complete(dreq->iocb, res, 0);
+		dreq->iocb->ki_complete(dreq->iocb, res);
 	}
 
 	complete(&dreq->completion);

fs/overlayfs/file.c

···
 	kmem_cache_free(ovl_aio_request_cachep, aio_req);
 }
 
-static void ovl_aio_rw_complete(struct kiocb *iocb, long res, long res2)
+static void ovl_aio_rw_complete(struct kiocb *iocb, long res)
 {
 	struct ovl_aio_req *aio_req = container_of(iocb,
 						   struct ovl_aio_req, iocb);
 	struct kiocb *orig_iocb = aio_req->orig_iocb;
 
 	ovl_aio_cleanup_handler(aio_req);
-	orig_iocb->ki_complete(orig_iocb, res, res2);
+	orig_iocb->ki_complete(orig_iocb, res);
 }
 
 static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter)

include/linux/fs.h

···
 	randomized_struct_fields_start
 
 	loff_t			ki_pos;
-	void (*ki_complete)(struct kiocb *iocb, long ret, long ret2);
+	void (*ki_complete)(struct kiocb *iocb, long ret);
 	void			*private;
 	int			ki_flags;
 	u16			ki_hint;