Re: [PATCH] usb: gadget: uvc: fix returnvar.cocci warnings

From: Andrzej Pietrasiewicz
Date: Wed Nov 23 2016 - 03:37:26 EST


Hi Laurent,

Thanks for a reminder. Please see inline.

W dniu 22.11.2016 o 18:27, Laurent Pinchart pisze:
Hi Andrzej and Julia,

Could one of you please submit a patch to fix this ?

On Thursday 17 Sep 2015 13:18:04 Andrzej Pietrasiewicz wrote:
Hi Julia,

W dniu 17.09.2015 o 10:57, Julia Lawall pisze:
Coccinelle suggests the following patch. But the code is curious. Is the
function expected to always return a failure value?

As a matter of fact it seems it should not return anything at all,
because...


Thank you for catching this. The function is not expected to always
return a failure value. Fortunately it does not matter anyway because

...because
the return value of the drop_link() operation is silently ignored by

And the Documentation/filesystems/configfs/configfs.txt says here:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/filesystems/configfs/configfs.txt#n397

"When unlink(2) is called on the symbolic link, the source item is
notified via the ->drop_link() method. Like the ->drop_item() method,
this is a void function and cannot return failure."

The ->drop_item() is indeed a void function, the ->drop_link() is
actually not. This, together with the fact that the value of ->drop_link()
is silently ignored suggests, that it is the ->drop_link() return
type that should be corrected and changed to void.

@Joel: What is your opinion? Should return type be changed to void?
Is there any reason why it should still be declared int?

I'm sending a copy of this mail to target-devel and linux-nvme,
because other potentially affected users of configfs live there.

AP