Re: [PATCH] block: t10-pi: fix -Wswitch warning

[Max Gurtovoy]

On 9/20/2019 9:05 AM, Nathan Chancellor wrote:
> On Thu, Sep 19, 2019 at 03:57:19PM +0200, Arnd Bergmann wrote:
> > Changing the switch() statement to symbolic constants made
> > the compiler (at least clang-9, did not check gcc) notice that
> > there is one enum value that is not handled here:
> >
> > block/t10-pi.c:62:11: error: enumeration value 'T10_PI_TYPE0_PROTECTION' not handled in switch [-Werror,-Wswitch]
> >
> > Add another case for the missing value and do nothing there
> > based on the assumption that the code was working correctly
> > already.
> >
> > Fixes: 9b2061b1a262 ("block: use symbolic constants for t10_pi type")
> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> > ---
> >   block/t10-pi.c | 2 ++
> >   1 file changed, 2 insertions(+)
> >
> > diff --git a/block/t10-pi.c b/block/t10-pi.c
> > index 0c0120a672f9..055fac923946 100644
> > --- a/block/t10-pi.c
> > +++ b/block/t10-pi.c
> > @@ -60,6 +60,8 @@ static blk_status_t t10_pi_verify(struct blk_integrity_iter *iter,
> >   		__be16 csum;
> >   
> >   		switch (type) {
> > +		case T10_PI_TYPE0_PROTECTION:
> > +			break;
> >   		case T10_PI_TYPE1_PROTECTION:
> >   		case T10_PI_TYPE2_PROTECTION:
> >   			if (pi->app_tag == T10_PI_APP_ESCAPE)
> > --
> > 2.20.0
> I didn't have the break in my local patch but I think this is more
> correct based on the description of the enums. Like Nick pointed out,
> there is no functional change because this value is not used in this
> file.
>
> Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx>

Hi,

we had a thread with Martin regarding this issue and we decided to set a 
default clause and add a BUG() in case we get there.

I've sent a patch with this fix.

-Max.