Re: [PATCH v2] vfs: Adjust indentation in remap_verify_area

[Nathan Chancellor]

On Wed, Dec 18, 2019 at 12:04:37PM +0100, David Sterba wrote:
> On Tue, Dec 17, 2019 at 10:16:35PM -0700, Nathan Chancellor wrote:
> > Clang's -Wmisleading-indentation caught an instance in remap_verify_area
> > where there was a trailing space after a tab. Remove it to get rid of
> > the warning.
> > 
> > Fixes: 04b38d601239 ("vfs: pull btrfs clone API to vfs layer")
> > Link: https://github.com/ClangBuiltLinux/linux/issues/828
> > Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> > ---
> > 
> > v1 -> v2:
> > 
> > * Trim warning and simplify patch explanation.
> > 
> >  fs/read_write.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/fs/read_write.c b/fs/read_write.c
> > index 5bbf587f5bc1..c71e863163bd 100644
> > --- a/fs/read_write.c
> > +++ b/fs/read_write.c
> > @@ -1757,7 +1757,7 @@ static int remap_verify_area(struct file *file, loff_t pos, loff_t len,
> >  	if (unlikely(pos < 0 || len < 0))
> >  		return -EINVAL;
> >  
> > -	 if (unlikely((loff_t) (pos + len) < 0))
> > +	if (unlikely((loff_t) (pos + len) < 0))
> 
> Instead of just fixing whitespace, can we please fix the undefined
> behaviour on this line? pos and len are signed types, there's a helper
> to do that in a way that's UB-safe.
> 
> And btw here's a patch:
> 
> https://lore.kernel.org/linux-fsdevel/20190808123942.19592-1-dsterba@xxxxxxxx/

I do not particularly care how this warning gets fixed, just that it
does. I will review that patch like Nick did.

Cheers,
Nathan