Re: [PATCH blktests] Fix build failure for discontiguous-io on 32-bit platforms

[Bart Van Assche <bvanassche@acm.org>]

On Mon, 2018-10-29 at 12:15 -0400, Theodore Ts'o wrote:
> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
> ---
>  src/discontiguous-io.cpp | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/discontiguous-io.cpp b/src/discontiguous-io.cpp
> index 5e0ee0f..a59c18d 100644
> --- a/src/discontiguous-io.cpp
> +++ b/src/discontiguous-io.cpp
> @@ -291,7 +291,7 @@ int main(int argc, char **argv)
>  			unsigned char *p = &*buf.begin();
>  			for (int i = 0; i < len / 4; i++)
>  				iov.append(p + 4 + i * 8,
> -					   std::min(4ul, len - i * 4));
> +					   std::min(4ul, (unsigned long) len - i * 4));
>  		} else {
>  			iov.append(&*buf.begin(), buf.size());
>  		}

Hi Ted,

Have you considered to change the data type of 'len' from size_t into unsigned long
instead of inserting this cast? That would make it clear that no integer truncation
happens in the iov.append() call.

Thanks,

Bart.