In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning
by explicitly adding a break statement instead of letting the code fall
through to the next case.

Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/block/xen-blkfront.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 48629d3433b4..34b028be78ab 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -2462,6 +2462,7 @@ static void blkback_changed(struct xenbus_device *dev,
 			break;
 		if (talk_to_blkback(dev, info))
 			break;
+		break;
 	case XenbusStateInitialising:
 	case XenbusStateInitialised:
 	case XenbusStateReconfiguring:
-- 
2.27.0

On 11/20/20 1:32 PM, Gustavo A. R. Silva wrote:
> In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning
> by explicitly adding a break statement instead of letting the code fall
> through to the next case.
>
> Link: https://github.com/KSPP/linux/issues/115
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
>  drivers/block/xen-blkfront.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
> index 48629d3433b4..34b028be78ab 100644
> --- a/drivers/block/xen-blkfront.c
> +++ b/drivers/block/xen-blkfront.c
> @@ -2462,6 +2462,7 @@ static void blkback_changed(struct xenbus_device *dev,
>  			break;
>  		if (talk_to_blkback(dev, info))
>  			break;
> +		break;
>  	case XenbusStateInitialising:
>  	case XenbusStateInitialised:
>  	case XenbusStateReconfiguring:


Reviewed-by Boris Ostrovsky <boris.ostrovsky@oracle.com>


(for patch 138 as well)


Although I thought using 'fallthrough' attribute was the more common approach.


-boris

On Fri, Nov 20, 2020 at 04:36:26PM -0500, boris.ostrovsky@oracle.com wrote:
> 
> On 11/20/20 1:32 PM, Gustavo A. R. Silva wrote:
> > In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning
> > by explicitly adding a break statement instead of letting the code fall
> > through to the next case.
> >
> > Link: https://github.com/KSPP/linux/issues/115
> > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> > ---
> >  drivers/block/xen-blkfront.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
> > index 48629d3433b4..34b028be78ab 100644
> > --- a/drivers/block/xen-blkfront.c
> > +++ b/drivers/block/xen-blkfront.c
> > @@ -2462,6 +2462,7 @@ static void blkback_changed(struct xenbus_device *dev,
> >  			break;
> >  		if (talk_to_blkback(dev, info))
> >  			break;
> > +		break;
> >  	case XenbusStateInitialising:
> >  	case XenbusStateInitialised:
> >  	case XenbusStateReconfiguring:
> 
> 
> Reviewed-by Boris Ostrovsky <boris.ostrovsky@oracle.com>
> 
> 
> (for patch 138 as well)

Thank you for both reviews, Boris.

> Although I thought using 'fallthrough' attribute was the more common approach.

I've got it. I will consider that for a future patch.

Thanks
--
Gustavo

On 20.11.20 19:32, Gustavo A. R. Silva wrote:
> In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning
> by explicitly adding a break statement instead of letting the code fall
> through to the next case.
> 
> Link: https://github.com/KSPP/linux/issues/115
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Applied to: xen/tip.git for-linus-5.11


Juergen

On Fri, Nov 20, 2020 at 12:32:58PM -0600, Gustavo A. R. Silva wrote:
> In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning
> by explicitly adding a break statement instead of letting the code fall
> through to the next case.
> 
> Link: https://github.com/KSPP/linux/issues/115
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
>  drivers/block/xen-blkfront.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
> index 48629d3433b4..34b028be78ab 100644
> --- a/drivers/block/xen-blkfront.c
> +++ b/drivers/block/xen-blkfront.c
> @@ -2462,6 +2462,7 @@ static void blkback_changed(struct xenbus_device *dev,
>  			break;
>  		if (talk_to_blkback(dev, info))
>  			break;
> +		break;

I would have added a fallthrough like it's done below in
XenbusStateClosed.

Also, FWIW, I think clang's fallthrough warnings are a bit too verbose.
Falling through to a break like the case here shouldn't cause a
warning IMO, falling through to anything != break should indeed cause
those warnings to appear.

Thanks, Roger.