Re: [PATCH] fstests: fix blksize_t printf format warnings across architectures

["Darrick J. Wong" <djwong@kernel.org>]

On Wed, Nov 20, 2024 at 07:40:41PM +0800, Anand Jain wrote:
> Fix format string warnings when printing blksize_t values that vary
> across architectures. The warning occurs because blksize_t is defined
> differently between architectures: aarch64 architectures blksize_t is
> int, on x86-64 it's long-int.  Cast the values to long. Fixes warnings
> as below.
> 
>  seek_sanity_test.c:110:45: warning: format '%ld' expects argument of type
>  'long int', but argument 3 has type 'blksize_t' {aka 'int'}
> 
>  attr_replace_test.c:70:22: warning: format '%ld' expects argument of type
>  'long int', but argument 3 has type '__blksize_t' {aka 'int'}
> 
> Signed-off-by: Anand Jain <anand.jain@oracle.com>

I waded through a whole bunch of glibc typedef and macro crud and
discovered that on x64 it can even be long long.  I think.  There were
so many levels of indirection that I am not certain that my analysis was
correct. :(

However, I don't see any harm in explicitly casting to long.  Nobody has
yet come up with a 8GB fsblock filesystem, so we're ok for now. :P

Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> ---
>  src/attr_replace_test.c | 2 +-
>  src/seek_sanity_test.c  | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/src/attr_replace_test.c b/src/attr_replace_test.c
> index 1218e7264c8f..5d560a633361 100644
> --- a/src/attr_replace_test.c
> +++ b/src/attr_replace_test.c
> @@ -67,7 +67,7 @@ int main(int argc, char *argv[])
>  	if (ret < 0) die();
>  	size = sbuf.st_blksize * 3 / 4;
>  	if (!size)
> -		fail("Invalid st_blksize(%ld)\n", sbuf.st_blksize);
> +		fail("Invalid st_blksize(%ld)\n", (long)sbuf.st_blksize);
>  	size = MIN(size, maxsize);
>  	value = malloc(size);
>  	if (!value)
> diff --git a/src/seek_sanity_test.c b/src/seek_sanity_test.c
> index a61ed3da9a8f..c5930357911f 100644
> --- a/src/seek_sanity_test.c
> +++ b/src/seek_sanity_test.c
> @@ -107,7 +107,7 @@ static int get_io_sizes(int fd)
>  		offset += pos ? 0 : 1;
>  	alloc_size = offset;
>  done:
> -	fprintf(stdout, "Allocation size: %ld\n", alloc_size);
> +	fprintf(stdout, "Allocation size: %ld\n", (long)alloc_size);
>  	return 0;
>  
>  fail:
> -- 
> 2.47.0
> 
>