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

From: David Sterba
Date: Wed Dec 18 2019 - 06:04:43 EST


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/