From: Jens Axboe <axboe@kernel.dk>
Date: Sat, 23 Oct 2021 07:52:23 -0600
Subject: usb: remove res2 argument from gadget code completions
Patch-mainline: v5.16-rc1
Git-commit: 4c3d8accdce26afa8089609593aa92965b500f72
References: jsc#PED-1183

The USB gadget code is the only code that every tried to utilize the
2nd argument of the aio completions, but there are strong suspicions
that it was never actually used by anything on the userspace side.

Out of the 3 cases that touch it, two of them just pass in the same
as res, and the last one passes in error/transfer in res like any
other normal use case.

Remove the 2nd argument, pass 0 like the rest of the in-kernel users
of kiocb based IO.

Link: https://lore.kernel.org/linux-block/20211021174021.273c82b1.john@metanate.com/
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/usb/gadget/function/f_fs.c |    2 +-
 drivers/usb/gadget/legacy/inode.c  |    6 ++----
 2 files changed, 3 insertions(+), 5 deletions(-)

--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -831,7 +831,7 @@ static void ffs_user_copy_worker(struct
 		kthread_unuse_mm(io_data->mm);
 	}
 
-	io_data->kiocb->ki_complete(io_data->kiocb, ret, ret);
+	io_data->kiocb->ki_complete(io_data->kiocb, ret, 0);
 
 	if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd)
 		eventfd_signal(io_data->ffs->ffs_eventfd, 1);
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -469,7 +469,7 @@ static void ep_user_copy_worker(struct w
 		ret = -EFAULT;
 
 	/* completing the iocb can drop the ctx and mm, don't touch mm after */
-	iocb->ki_complete(iocb, ret, ret);
+	iocb->ki_complete(iocb, ret, 0);
 
 	kfree(priv->buf);
 	kfree(priv->to_free);
@@ -496,11 +496,9 @@ static void ep_aio_complete(struct usb_e
 		kfree(priv->to_free);
 		kfree(priv);
 		iocb->private = NULL;
-		/* aio_complete() reports bytes-transferred _and_ faults */
-
 		iocb->ki_complete(iocb,
 				req->actual ? req->actual : (long)req->status,
-				req->status);
+				0);
 	} else {
 		/* ep_copy_to_user() won't report both; we hide some faults */
 		if (unlikely(0 != req->status))