On Tue, Apr 01, 2025 at 08:22:33PM -0400, Theodore Ts'o wrote:
> On Fri, Feb 21, 2025 at 07:57:57PM +0100, Pavel Reichl wrote:
> > The function filesize() was declared with a return type of 'long' but
> > defined with 'off_t'. This mismatch caused build issues due to type
> > incompatibility.
> >
> > This commit updates the declaration to match the definition, ensuring
> > consistency and preventing potential compilation errors.
> >
> > Fixes: 73fb78e5ee8 ("mkfs: support copying in large or sparse files")
>
> I had run into this issue when building xfsprogs on i386, and had
> investigated the compilation failure before finding this commit in
> origin/for-next. But in my fix, I also found that there was a missing
> long -> off_t conversion in setup_proto():
>
> diff --git a/mkfs/proto.c b/mkfs/proto.c
> index 7f56a3d8..52ef64ff 100644
> --- a/mkfs/proto.c
> +++ b/mkfs/proto.c
> @@ -61,7 +61,7 @@ setup_proto(
> char *buf = NULL;
> static char dflt[] = "d--755 0 0 $";
> int fd;
> - long size;
> + off_t size;
>
> if (!fname)
> return dflt;
>
> ... since setup_proto() also calls filesize():
>
> if ((fd = open(fname, O_RDONLY)) < 0 || (size = filesize(fd)) < 0) {
>
> How important is it fix this up? I can send a formal patch if that
> would be helpful, but commit a5466cee9874 is certainly enough to fix
> the build failure so maybe it's enough.
Yes, this is important -- off_t can be larger than long, and that can
result in incorrect truncations. I hope that nobody will ever pass mkfs
a 5GB protofile on 32-bit, but at least the C type usage could be
correct.
--D
>
> Cheers,
>
> - Ted
>
